Battery device and electric equipment

Abstract

The utility model relates to the technical field of batteries, and discloses a battery device and electric equipment, and a battery pack comprises a U-shaped coating shell, a plurality of soft package battery monomers and a convergence bracket; the U-shaped coating shell is connected with the box body, the confluence support is arranged on the U-shaped coating shell and is connected with the U-shaped coating shell through the connecting part, the U-shaped coating shell, the box body and the confluence support jointly form an accommodating space, and the plurality of soft package battery monomers are arranged in the accommodating space and are electrically connected through the confluence support; wherein the U-shaped coating shell is provided with a pressure relief part, the shear strength of the connecting part is larger than a first preset value, the first preset value is larger than or equal to 0.1 Mpa, the bonding strength of the adhesive layer is larger than a second preset value, and the second preset value is larger than or equal to 1 Mpa. Therefore, in the directional pressure relief process, the probability of connection failure between the connecting part and the U-shaped coating shell as well as between the U-shaped coating shell and the adhesive layer is lower, so that the reliability and the stability of directional pressure relief are improved, and the reliability of the battery device is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery device and electrical equipment. Background Art

[0002] In the related art, there is a problem of high difficulty in directional pressure relief of soft-pack battery cells, which affects the further improvement of the reliability of the soft-pack battery device. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to provide a battery device and an electrical device, wherein the battery device can stably achieve directional pressure relief and has higher reliability.

[0004] In the first aspect, the present application provides a battery device comprising: a case and a battery pack, the battery pack comprising a U-shaped covering shell, a plurality of soft-pack battery cells and a bus bracket; the U-shaped covering shell and the case are bonded together by an adhesive layer, the bus bracket is arranged on the U-shaped covering shell and is connected to the U-shaped covering shell through a connecting portion, the U-shaped covering shell, the case and the bus bracket together form a accommodating space, a plurality of soft-pack battery cells are arranged in the accommodating space and are electrically connected through the bus bracket; wherein, the U-shaped covering shell has a pressure relief portion, the shear strength of the connecting portion is greater than a first preset value, the first preset value is greater than or equal to 0.1 MPa, and the bonding strength of the adhesive layer is greater than a second preset value, the second preset value is greater than or equal to 1 MPa.

[0005] According to the battery device of the embodiment of the present application, by making the shear strength of the connecting portion greater than a first preset value and the bonding strength of the adhesive layer greater than a second preset value, when thermal runaway occurs inside the battery pack, the pressure relief portion can be caused to rupture preferentially for directional pressure relief. During the directional pressure relief process, the probability of connection failure between the connecting portion and the U-shaped covering shell, and between the U-shaped covering shell and the adhesive layer is lower, thereby improving the reliability and stability of the directional pressure relief, thereby improving the reliability of the battery device.

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

[0007] In the above technical solution, the connecting portion is connected to at least one of the first plate and the second plate to improve the connection strength between the bus bracket and the U-shaped covering shell, thereby improving the directional pressure relief stability and improving the reliability of the battery device.

[0008] According to some embodiments of the present application, the connecting portion includes a plug-in column, and the connecting portion is inserted into a slot formed on the first board and / or the second board.

[0009] In the above technical solution, the bus bracket and the U-shaped covering shell can be plugged in and fastened together, which can improve the connection strength while reducing the difficulty of assembly and improving the assembly efficiency.

[0010] According to some embodiments of the present application, the orthographic projection size of the plug-in post toward the slot is larger than the opening size of the slot, so that the plug-in post and the slot have an interference fit.

[0011] In the above technical solution, in an embodiment in which both the first plate and the second plate are connected to the connecting portion, the slot may be an L-shaped slot. In an embodiment in which the first plate or the second plate is connected to the connecting portion, the slot may include a straight slot, and the opening size of the slot is L1. The sum of the thickness dimensions of the ends or plug-in columns of the first plate and / or the second plate that cooperate with the slot is L2, and L1 is greater than L2, so that the connecting portion and the first plate and / or the second plate are constructed as an interference fit, thereby improving the connection strength between the connecting portion and the U-shaped covering shell, thereby improving the stability of directional pressure relief, and improving the reliability of the battery device.

[0012] According to some embodiments of the present application, the projection size of the plug-in post toward the slot is larger than the opening size by 0.2 mm to 1 mm.

[0013] In the above technical solution, the interference fit size between the plug-in post and the slot is not less than 0.2mm, which can improve the connection reliability and stability of the plug-in post and the slot, and avoid insufficient connection strength between the bus bracket and the U-shaped covering shell due to the interference amount being within the tolerance range. The interference fit size between the plug-in post and the slot is not greater than 1mm, which can reduce the difficulty of assembly and the probability of structural damage to the plug-in post during assembly, thereby extending the service life of the bus bracket.

[0014] According to some embodiments of the present application, the connecting portion includes a lap plate connected to the first plate and / or the second plate.

[0015] In the above technical solution, in an embodiment where the connecting portion includes a lap plate, the connecting portion can be fixedly connected to the first plate and / or the second plate by one or more combinations of screwing, gluing or welding, and the connection strength between the connecting portion and the U-shaped covering shell can be improved to improve the directional pressure relief stability and improve the reliability of the battery device.

[0016] According to some embodiments of the present application, the overlap size between the overlap plate and the first plate and / or the second plate is 1 mm-5 mm.

[0017] In the above technical solution, the overlap size is not less than 1 mm, which can improve the connection strength between the connection part and the U-shaped covering shell, reduce the probability of cold welding, poor welding, and insufficient bonding strength, and make the overlap size not more than 5 mm. Under the premise of ensuring the connection strength, the space occupied by the connection part can also be reduced to take into account the energy density of the battery pack.

[0018] According to some embodiments of the present application, the lap plate is fixed to the first plate and / or the second plate by adhesive bonding, welding or screwing.

[0019] According to some embodiments of the present application, the connecting portion includes a first clamping structure, and the length end of the first plate and / or the second plate is formed with a second clamping structure that is clamped and matched with the first clamping structure.

[0020] According to some embodiments of the present application, the bus bracket includes: an insulating body and a sealing portion, the sealing portion is located between the insulating body and the soft-pack battery cell, the connecting portion is connected to the insulating body and is located on at least one side edge of the insulating body, a first groove and a second groove are formed on the insulating body, the first groove is located on the side surface of the insulating body facing the soft-pack battery cell, the second groove is located on the adjacent side surface of the insulating body and passes through the insulating body, the first groove is connected to the second groove, and the first groove is suitable for accommodating the pole ear, and the second groove is suitable for accommodating the bus bar body electrically connected to the pole ear.

[0021] In the above technical solution, the insulating body can be constructed as an insulating structure such as a plastic part or a rubber part, the connecting part can be integrally formed with the insulating body, or the connecting part can be constructed as a metal insert and embedded in the insulating body, so as to improve the connection strength and reliability between the bus bracket and the U-shaped covering shell by the connecting part constructed as a metal insert. At the same time, the insulating body can be used to separate the connecting part from the tab, bus bar, etc., which can also reduce the probability of short circuit in the battery pack and improve the reliability of the battery pack.

[0022] At the same time, by providing a sealing portion between the insulating body and the U-shaped covering shell and the soft-pack battery cell, the sealing performance of the battery pack can be improved, thereby improving the reliability and stability of the battery pack. The provision of the first groove and the second groove on the insulating body can make the electrical connection between the busbar body and the tab less difficult, and the electrical connection between multiple soft-pack battery cells and the electrical connection between adjacent battery packs less difficult.

[0023] According to some embodiments of the present application, when the energy density of the soft-pack battery cell is 450 Wh / L to 600 Wh / L, the shear strength of the connection portion is 0.1 MPa to 0.2 MPa, and the bonding strength of the adhesive layer is 1 MPa to 2.5 MPa;

[0024] When the energy density of the soft-pack battery cell is 600Wh / L~700Wh / L, the shear strength of the connection is 0.2Mpa~0.3Mpa, and the bonding strength of the glue layer is 2.5Mpa~5.5Mpa;

[0025] When the energy density of the soft-pack battery cell is greater than 700Wh / L, the shear strength of the connection is 0.3Mpa~0.5Mpa, and the bonding strength of the glue layer is 5.5Mpa~10.5Mpa.

[0026] In the above technical solution, the shear strength of the connection part can be reasonably set based on the energy density, which can avoid the connection strength between the connection part and the covering shell being too low and reduce the probability of failure of the connection part to ensure that the connection strength between the connection part and the U-shaped covering shell can meet the directional pressure relief requirements. It can also avoid the shear strength being too high to avoid structural redundancy and reduce costs. At the same time, the bonding strength of the glue layer can be reasonably set to reduce the connection failure between the battery pack and the box, especially the probability of connection failure between the U-shaped covering shell and the box, to meet the directional pressure relief requirements.

[0027] According to some embodiments of the present application, there are multiple pressure relief portions, and the multiple pressure relief portions are arranged at intervals in the length direction and / or width direction of the first plate.

[0028] In the above technical solution, the multiple weak parts on each soft-pack battery cell can be provided with corresponding pressure relief parts, so that the high-temperature gas and fire flow buffered by the exhaust channel can be discharged directly through the corresponding pressure relief parts, thereby increasing the discharge speed and reducing the residence time of the high-temperature gas and fire flow in the exhaust channel during the discharge process, thereby reducing the spread speed of thermal runaway between adjacent soft-pack battery cells in the battery pack and improving the reliability of the battery pack.

[0029] According to some embodiments of the present application, the first plate is configured as a straight plate or a curved plate.

[0030] According to some embodiments of the present application, a soft-pack battery cell includes: a flexible shell and an electrode assembly disposed in the flexible shell, the flexible shell having a side surface opposite to a large surface of the electrode assembly and a circumferential surface avoiding the large surface, and the second plate is opposite to the side surface.

[0031] According to some embodiments of the present application, a projected contour area of ​​the second plate facing the side surface of the flexible housing is smaller than or equal to an area of ​​the side surface.

[0032] In the above technical solution, on the one hand, it can avoid the second plate being too large, which makes the second surface unable to connect with the box body, and can improve the fixation stability and reliability of the battery pack in the box body. On the other hand, the material used for the second plate can be less, and the material cost of the battery pack and the battery device can also be reduced.

[0033] According to some embodiments of the present application, a weak portion is formed on the circumferential surface, the weak portion is opposite to the first plate, and the pressure relief portion is at least partially opposite to the weak portion.

[0034] In the above technical solution, on the one hand, the gas and fire flow generated after thermal runaway of the soft-pack battery cell can be discharged in a direction and orderly to reduce damage, especially secondary damage. On the other hand, the communication path between the pressure relief zone and the pressure relief part is shorter, which can achieve rapid discharge. At the same time, the gas and fire flow stays in the U-shaped covering shell for a shorter time, which has less impact on other soft-pack battery cells around the thermal runaway soft-pack battery cell, and can further reduce the spread speed of thermal runaway, thereby improving the reliability of battery packs and battery devices.

[0035] According to some embodiments of the present application, the first plate is spaced apart from a side of the circumferential surface having the weak portion to define an exhaust channel.

[0036] In the above technical solution, the high-temperature gas and fire flow generated after the weak part ruptures can be first discharged to the exhaust channel, and after preliminary buffering through the exhaust channel, it can be discharged through the pressure relief part. This can reduce the pressure of the high-temperature gas and fire flow after flowing out of the pressure relief part, thereby reducing the impact and damage after thermal runaway of the soft-pack battery cell.

[0037] According to some embodiments of the present application, the U-shaped covering shell is constructed as an aluminum shell or a stainless steel shell.

[0038] In the above technical solution, in some embodiments, the U-shaped covering shell is constructed as an aluminum shell, and in other embodiments, the U-shaped covering shell is constructed as a stainless steel shell, so that the temperature resistance and structural strength of the U-shaped covering shell are much higher than those of the flexible shell. By using the U-shaped covering shell with certain structural strength and rigidity to support and protect the soft-pack battery cell outside the soft-pack battery cell, the structural strength of the battery pack can be improved, and the thermal runaway propagation speed between adjacent battery packs can be reduced, thereby improving the reliability of the battery device.

[0039] According to some embodiments of the present application, an end surface of the soft-pack battery cell away from the first plate is connected to the box body through an adhesive layer.

[0040] According to some embodiments of the present application, the box body has a bottom plate, and the bottom plate is connected to the soft-pack battery cell through an adhesive layer.

[0041] In the above technical solution, the bottom plate of the box body is connected to the second surface of the soft-pack battery cell through the adhesive layer to fix the battery pack on the box body, thereby improving the fixing stability and reliability of the battery pack.

[0042] According to some embodiments of the present application, the bottom plate includes a cold plate, and the glue layer is located between the cold plate and the plurality of soft-pack battery cells.

[0043] In the above technical solution, the adhesive layer is constructed of structural adhesive, and the bottom plate provided with a cold plate is connected to the soft-pack battery cell. On the premise of achieving stable and reliable fixation of the battery pack in the box, the temperature of the battery pack can also be regulated by the cold plate, so that the battery pack can operate at a suitable temperature, which can improve the working stability and reliability of the battery pack, reduce the probability of overheating of the battery pack, and thus reduce the probability of thermal runaway of the battery pack, thereby improving the reliability of the battery pack and even the battery device.

[0044] According to some embodiments of the present application, the glue layer includes: a glue layer body and a glue overflow portion, the glue overflow portion is located on the side of the glue layer body facing the multiple soft-pack battery cells, and is located between adjacent soft-pack battery cells and / or between the soft-pack battery cells and the second plate.

[0045] In the above technical solution, when the structural adhesive is used to connect and fix the soft-pack battery cells to the cold plate, at least part of the adhesive layer overflows between adjacent soft-pack battery cells and / or between the second plate and the soft-pack battery cells, and forms an overflowing adhesive portion. By setting the overflowing adhesive portion, not only can the area between the adhesive layer and the soft-pack battery cells, and between the adhesive layer and the second plate be increased, so as to improve the fixation stability and reliability of the battery pack on the box, but also the gaps between adjacent soft-pack battery cells and between the soft-pack battery cells and the second plate can be filled by the overflowing adhesive portion to achieve the limitation of the soft-pack battery cells and the U-shaped covering shell, thereby reducing the movement of the battery pack in the box and reducing the movement of the soft-pack battery cells in the U-shaped covering shell.

[0046] According to some embodiments of the present application, the soft-pack battery cell is any one of a lithium iron phosphate battery cell, a ternary lithium battery cell, and a solid-state battery cell.

[0047] In the above technical solution, in the embodiment of the present application constructed as a lithium iron phosphate battery cell, the reliability of the soft-pack battery cell can be improved and the cycle life of the soft-pack battery cell can be extended. In the embodiment of the present application constructed as a ternary lithium battery cell, the energy density of the soft-pack battery cell can be improved and the cruising range can be increased. In the embodiment of the present application constructed as a solid-state soft-pack battery cell, not only the energy density can be improved, but also the reliability can be improved.

[0048] In a second aspect, the present application provides an electrical device, including: the battery device in the above embodiment.

[0049] According to some embodiments of the present application, the electric device is a vehicle.

[0050] In the above technical solution, the electrical equipment is constructed as a vehicle, and the battery device has a higher energy density and higher reliability, which can improve the vehicle's driving reliability while increasing the vehicle's cruising range.

[0051] According to some embodiments of the present application, the battery device is integrated into the chassis of the vehicle, and the top plate of the box helps to define the vehicle body floor.

[0052] In the above technical solution, the electrical equipment can be a vehicle, and the battery device can be integrated on the chassis of the vehicle, that is, the body structure is a split body, the upper body and the integrated intelligent chassis are assembled, and the battery device forms a part of the integrated intelligent chassis, so that the top plate of the box can also participate in defining the body floor, which can save meaningless multi-layer plate stacking, reduce material costs, and make the space occupancy of the chassis more reasonable. The space inside the chassis for accommodating the battery device is larger and the energy density is higher.

[0053] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0055] Figure 1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0056] Figure 2 is a schematic diagram of a battery device according to an embodiment of the present application;

[0057] Figure 3 is a schematic diagram of a battery pack according to a first embodiment of the present application;

[0058] Figure 4 is another schematic diagram of a battery pack according to the first embodiment of the present application;

[0059] Figure 5 is a schematic diagram of a busbar support according to a first embodiment of the present application;

[0060] Figure 6 is a schematic diagram of a battery pack according to a second embodiment of the present application;

[0061] Figure 7 is another schematic diagram of a battery pack according to a second embodiment of the present application;

[0062] Figure 8 is a schematic diagram of a busbar support according to a second embodiment of the present application;

[0063] Figure 9 is a schematic diagram of a battery pack according to a third embodiment of the present application;

[0064] Figure 10 is a schematic diagram of a battery cell according to an embodiment of the present application;

[0065] Figure 11 Schematic diagram of the cooperation between the U-shaped cover and the battery cell according to an embodiment of the present application;

[0066] Figure 12 It is a schematic diagram of the cooperation between the box and the battery pack according to an embodiment of the present application.

[0067] Reference numerals:

[0068] Battery device 100,

[0069] Box body 10, bottom plate 11, glue layer 12, glue layer body 121, glue overflow part 122,

[0070] Battery pack 20, U-shaped cover shell 21, first plate 211, pressure relief portion 2111, second plate 212, soft-pack battery cell 22, flexible shell 221, side surface 2211, circumferential surface 2212, weak portion 2213, electrode assembly 222, bus bracket 23, connecting portion 231, insulating body 232, first groove 2321, second groove 2322, sealing portion 233,

[0071] Electrical equipment 200, motor 300, controller 400,

[0072] Exhaust channel a. DETAILED DESCRIPTION

[0073] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0074] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0075] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0076] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0077] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0078] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0079] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0080] In the description of the present invention, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact via another feature therebetween.

[0081] In the description of the present invention, a first feature “above”, “above” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0082] The term "plurality" used in this application refers to two or more (including two).

[0083] The battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be recharged to activate the active material after the battery cell is discharged and can be used continuously.

[0084] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0085] The battery device mentioned in the embodiments of the present application may include one or more battery packs for providing voltage and capacity. The battery pack may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0086] In some embodiments, a battery pack is generally formed by arranging a plurality of battery cells.

[0087] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery packs housed in the case.

[0088] As an example, the battery pack may be accommodated in the case by being fixed in the case.

[0089] As an example, the housing may include a first housing and a second housing. The first housing and the second housing engage to form an enclosed space within the housing to accommodate the battery pack. Enclosed herein means covered or closed, and may be sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0090] As an example, the box may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame to form a closed space inside the box to accommodate the battery pack.

[0091] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0092] The technical solutions described in the embodiments of the present application are applicable to battery devices and electrical equipment using the battery devices.

[0093] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0094] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0095] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application. A battery device 100 is disposed within the vehicle, and can be located at the bottom, front, or rear of the vehicle. Battery device 100 can be used to power the vehicle, for example, as the vehicle's operating power source.

[0096] The vehicle may further include a controller 400 and a motor 300 . The controller 400 is used to control the battery device 100 to supply power to the motor 300 . The motor 300 serves as a load, for example, to meet the power requirements for starting, navigating, and driving the vehicle.

[0097] In some embodiments of the present application, the battery device 100 can not only serve as the operating power source of the vehicle, but also serve as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0098] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of the present application. The battery device 100 includes a housing 10 for accommodating battery cells.

[0099] Among them, the box body 10 is a component for accommodating battery cells. The box body 10 provides a placement space for the battery pack 20. The box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a tray and a cover plate, and the tray and the cover plate cover each other to define a placement space for accommodating battery cells. The tray and the cover plate can be of various shapes, such as a rectangular parallelepiped, a cylinder, etc. The tray can be a hollow structure with one side open, and the cover plate can also be a hollow structure with one side open. The open side of the cover plate covers the open side of the tray, thereby forming a box body 10 with a placement space. The tray can also be a hollow structure with one side open, and the cover plate can be a plate-shaped structure. The cover plate covers the open side of the tray, thereby forming a box body 10 with a placement space.

[0100] As an example, the battery cell may be a pouch battery cell 22 .

[0101] In the battery device 100, there can be one or more battery cells. Multiple battery cells are assembled into a battery pack 20 via 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, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be connected in series, in parallel, or in a hybrid configuration to form a battery pack 20. The battery packs 20 are then assembled into a single unit and housed within the housing 10.

[0102] The battery cell is the smallest energy unit of the battery device 100 , and includes a flexible housing 221 and an electrode assembly 222 disposed within the flexible housing 221 .

[0103] The internal environment formed by the flexible shell 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 shell 221 for injecting electrolyte and the electrode assembly 222 into the shell.

[0104] The electrode assembly 222 is a component in the battery cell where electrochemical reactions occur. One or more electrode assemblies 222 may be contained in the flexible housing 221. 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 parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 222, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located at both ends of the main body, respectively. Bus brackets 23 are provided at both ends of the battery pack 20. During the charge and discharge process of the battery device 100, the positive active material and the negative active material react with the electrolyte, and the tabs are connected to the bus bracket 23 to form a current loop.

[0105] The positive electrode sheet may include a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.

[0106] As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector.

[0107] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, the metal foil may include stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, titanium, or silver-treated aluminum or stainless steel. A composite current collector may include a polymer base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys) onto a polymer substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0108] As an example, when the soft-pack battery cell 22 of an embodiment of the present application 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 for improving the energy density of the soft-pack battery cell 22. However, the present application is not limited to these materials; other conventional materials that can be used as battery positive electrode film layers may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0109] 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)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0110] Layered transition metal oxides include those of the general formula Li a Ni b Co c M d O e A f At least one compound and its modified compound. 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, further optionally, 0.75≤b≤0.98.

[0111] Examples of layered transition metal oxides include, but are not limited to, lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 )、LiNi 0.9 Co 0.05 Mn 0.05 O2 (also referred to as Ni90), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0112] When the soft-pack battery cell 22 of the embodiment of the present application 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, polyanion materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian blue materials.

[0113] As an example, the positive active material for sodium ion batteries may include NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, 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, general formula X p M' q (PO4) r O x Y 3-x At least one of the materials. p M' q (PO4) r O x Y 3-x wherein 0<p≤4, 0<q≤2, 1≤r≤3, 0≤x≤2, X comprises 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 halogen anion, optionally at least one of F, Cl and Br.

[0114] In the embodiment of the present application, the modified compounds of the above-mentioned positive electrode active materials can be doping modification and / or surface coating modification of the positive electrode active materials, such as carbon coating modification, fast ion conductor coating modification, etc.

[0115] The charge and discharge process of the soft-pack battery cell 22 is accompanied by the deintercalation and consumption of active ions such as Li. The molar content of Li in the soft-pack battery cell 22 varies when the soft-pack battery cell 22 is discharged to different states. In the examples of this application, the molar content of Li in the positive electrode active materials listed is the initial state of the material, that is, the state before the material is added. When the positive electrode active material is used in the battery system, the molar content of Li may change after charge and discharge cycles.

[0116] In the examples of the present application regarding the positive electrode active materials, the molar content of oxygen O is only a theoretical value. Lattice oxygen release will cause the molar content of oxygen O to change. In practice, the molar content of oxygen O will fluctuate.

[0117] In the examples of this application, the element contents in the positive electrode active material have meanings well known in the art and can be measured using equipment and methods known in the art. For example, in accordance with EPA 6010D-2014, the content can be measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, Thermo ICAP7400). First, 0.4 g of the positive electrode active material was weighed and 10 ml of 50% aqua regia was added. The mixture was then placed on a plate at 180°C for 30 minutes. After digestion on the plate, the volume was adjusted to 100 ml, and quantitative analysis was performed using a standard curve method.

[0118] In some embodiments, a positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or the like. When a metal foam is used as the positive electrode, a positive electrode film layer may or may not be provided on the surface of the metal foam. As an example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0119] In some embodiments, the positive electrode film layer may further optionally include a positive electrode conductive agent. The present invention does not particularly limit the type of the positive electrode conductive agent. For example, the positive electrode conductive agent may include at least one of 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%.

[0120] In some embodiments, the positive electrode film layer may also optionally include a positive electrode binder. The present embodiments do not particularly limit the type of positive electrode binder. For example, the positive electrode binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylic resin. In some embodiments, the mass percentage of the positive electrode binder in the positive electrode film layer is ≤5 wt%.

[0121] The positive electrode film layer is typically formed by coating a positive electrode slurry onto a positive electrode current collector, drying it, and cold pressing it. The positive electrode slurry is typically formed by dispersing the positive electrode active material, an optional conductive agent, an optional binder, and any other components in a solvent and stirring them uniformly. The solvent can be, but is not limited to, N-methylpyrrolidone (NMP).

[0122] 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, wherein the negative electrode film layer includes a negative electrode active material.

[0123] As an example, the negative electrode current collector has two surfaces opposite to each other in its 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.

[0124] As examples, the negative electrode current collector can be a metal foil, metal foam, or composite current collector. For example, the metal foil can include silver-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymer base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) onto a polymer substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0125] As an example, the negative electrode active material may be a negative electrode active material known in the art for soft-pack battery cells 22. As an example, the negative electrode active material may include at least one of the following materials: a carbon material (for example, a carbon material including at least one of artificial graphite, natural graphite, soft carbon, and hard carbon), a silicon-based material, a tin-based material, and lithium titanate. The silicon-based material may include at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material may include at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as battery negative electrode film layers may also be used. These negative electrode film layers may be used alone or in combination of two or more.

[0126] In some embodiments, the negative electrode active material includes silicon, which may be present in the form of a silicon-based material. For example, the silicon-based material may include at least one of elemental silicon, a silicon-oxygen compound, a silicon-carbon complex, a silicon-nitrogen complex, and a silicon alloy. The introduction of silicon can increase the energy density of the pouch cell 22.

[0127] In some embodiments, the mass content of silicon in the negative electrode film layer is 1 wt% to 32 wt%, optionally 2 wt% to 19 wt%, and further optionally 6 wt% to 13 wt%. In the soft-pack battery cell 22 system, when the mass content of silicon is within the above range, the energy density of the soft-pack battery cell 22 can be improved.

[0128] In the embodiments of the present application, the mass content of silicon in the negative electrode film layer has a meaning well known in the art and can be detected by using equipment and methods well known in the art. For example, the negative electrode plate is placed in a solvent such as water for immersion, the negative electrode active material is separated from the negative electrode current collector, and the negative electrode active material is obtained by filtration. The negative electrode active material is measured using an ICAP7400 inductively coupled plasma-emission spectrometer of ThermoFisher Scientific, USA, with reference to GB / T30902-2014 standard to obtain the silicon content.

[0129] In some embodiments, the negative electrode film layer may further optionally include a negative electrode conductive agent. The present invention does not particularly limit the type of the negative electrode conductive agent. For example, the negative electrode conductive agent may include at least one of 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%.

[0130] In some embodiments, the negative electrode film layer may also optionally include a negative electrode binder. The present embodiments do not specifically limit the type of negative electrode binder. For example, the negative electrode binder may include at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based 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 weight percentage of the negative electrode binder in the negative electrode film layer is ≤5%.

[0131] In some embodiments, the negative electrode film layer may optionally include other additives. For example, these additives may include thickeners, such as sodium carboxymethylcellulose (CMC-Na), PTC thermistor materials, and the like. In some embodiments, the mass percentage of these additives in the negative electrode film layer is ≤ 2 wt%.

[0132] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0133] In some embodiments, the separator includes a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0134] The embodiments of the present application have no particular limitation on the type of isolation membrane, and any known isolation membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0135] In some embodiments, the material of the separator may include one or more of glass fiber, non-woven 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.

[0136] In some embodiments, the separator may include a porous base membrane and a coating layer disposed on at least one side of the porous base membrane, and the coating layer may include at least one of inorganic particles or organic particles.

[0137] The porous base membrane may include one or more of polyethylene and polypropylene.

[0138] The inorganic particles have good heat resistance and can improve the overall heat resistance of the separator. Within the operating voltage range of the sodium-ion battery, the inorganic particles essentially do not undergo oxidation and reduction reactions with metal dendrites. In other words, the inorganic particles are configured to not undergo oxidation and reduction reactions with alkali metals and / or alkaline earth metals at the nominal voltage of the sodium-ion battery.

[0139] 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.

[0140] 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, polyaramid, polyamideimide, polyimide, copolymer of butyl acrylate and ethyl methacrylate, and mixtures thereof.

[0141] In some embodiments, the pouch cell 22 further includes an electrolyte.

[0142] During the charge and discharge process of a battery cell, active ions are embedded and released back and forth between the positive and negative electrodes, and the electrolyte conducts the active ions between the positive and negative electrodes. The present embodiment does not specifically limit the type of electrolyte, and the electrolyte can be selected based on actual needs.

[0143] The electrolyte solution includes an electrolyte salt and a solvent. The types of the electrolyte salt and the solvent are not particularly limited and can be selected according to actual needs.

[0144] 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, or additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, and additives that improve battery low-temperature power performance.

[0145] For example, the additive includes at least one of a cyclic carbonate compound containing an unsaturated bond, a sulfate compound, a sulfite compound, a sultone compound, a disulfonic acid compound, a nitrile compound, an aromatic compound, an isocyanate compound, a phosphazene compound, an acid anhydride, a cyclic acid anhydride compound, a phosphite compound, a phosphate compound, a borate ester, and a carboxylate compound.

[0146] In the related art, a pressure relief portion 2111 is provided on the soft-pack battery cell 22, and a pressure relief portion 2111 is provided on the U-shaped covering shell 21. The pressure relief portion 2111 and the pressure relief portion 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 bus bracket 23 and the U-shaped covering shell 21 is prone to failure under the action of pressure, and the adhesive layer 12 between the battery pack 20 and the box body 10 is also prone to adhesion failure, resulting in failure of the connection between the bus bracket 23 and the U-shaped covering shell 21, and then resulting in failure of the directional pressure relief, which is likely to cause secondary damage and reduce the reliability of the battery pack 20.

[0147] Based on this, the present application proposes a battery device 100, in which the connection strength between the U-shaped covering shell 21 and the bus bracket 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 the first preset value. The battery pack 20 and the box body 10 are bonded by the adhesive layer 12, and the bonding strength is greater than the second preset value. When the pressure relief part 2111 is relieving pressure, the probability of connection failure between the U-shaped covering shell 21 and the bus bracket 23, and between the U-shaped covering shell 21 and the box body 10 can be reduced, so as to improve the stability and reliability of directional pressure relief, reduce secondary damage, and improve the reliability of the battery device 100.

[0148] Reference below Figures 1-12 A battery device 100 and a powered device 200 according to an embodiment of the present invention are described.

[0149] Combine Figure 2 、 Figure 11 and Figure 12 As shown, the present application provides a battery device 100 , including: a box body 10 and a battery pack 20 , wherein the battery pack 20 is disposed in the box body 10 .

[0150] Among them, Figure 3 、 Figure 6 and Figure 9 As shown, the battery pack 20 includes a U-shaped covering shell 21, a plurality of soft-pack battery cells 22 and a bus bracket 23. The U-shaped covering shell 21 is bonded to the case 10 by an adhesive layer 12 (the adhesive layer 12 can be constructed as a structural adhesive). The bus bracket 23 is arranged on the U-shaped covering shell 21 and is connected to the U-shaped covering shell 21 through a connecting portion 231. The U-shaped covering shell 21, the case 10 and the bus bracket 23 together form a accommodating space. The plurality of soft-pack battery cells 22 are arranged in the accommodating space and are electrically connected through the bus bracket 23.

[0151] Specifically, see Figure 4 、 Figure 6 、 Figure 7 as well as Figure 10As shown, tabs are extended from both ends of the length of the soft-pack battery cell 22, and there are two bus brackets 23. The two bus brackets 23 are respectively arranged at both ends of the length of the soft-pack battery cell 22 and are electrically connected to the two tabs respectively to realize the electrical connection between the soft-pack battery cell 22 and the outside world. The bus bracket 23 is connected to the U-shaped covering shell 21 and defines an accommodating space. The soft-pack battery cell 22 is arranged in the accommodating space to provide support and protection on the surrounding side of the soft-pack battery cell 22 through the U-shaped covering shell 21 and the bus bracket 23.

[0152] Furthermore, the U-shaped covering shell 21 has a pressure relief portion 2111. The pressure relief portion 2111 is used to discharge the high-temperature and high-pressure gas and gas-entrained particulate matter (i.e., high-temperature gas fire flow) in the accommodating space through the pressure relief portion 2111 when thermal runaway occurs in the soft-pack battery cell 22. This can achieve directional pressure relief of the battery pack 20, so that the battery pack 20 can be pressure-relieved in the direction of the pressure relief portion 2111, thereby achieving orderly pressure relief, reducing secondary damage to the insulating interface of the battery device 100, and slowing the spread of thermal runaway.

[0153] It should be pointed out that the insulating interface of the battery device 100 includes: the insulating structure between adjacent soft-pack battery cells 22, the insulating structure between adjacent battery packs 20, the insulating structure between the battery pack 20 and surrounding components, etc., and the orderly discharge of high-temperature gas and fire flow can reduce the impact on the insulating interface when the battery pack 20 is depressurized, thereby reducing the probability of secondary damage and improving reliability.

[0154] It can be understood that when thermal runaway occurs in the soft-pack battery cell 22, when the high-pressure gas fire flow acts on the connecting portion 231 or the connecting area between the connecting portion 231 and the U-shaped covering shell 21, the shear force that the connecting portion 231 can withstand is less than the force of the high-pressure gas fire flow, which easily leads to the probability of failure of the connection between the connecting portion 231 and the U-shaped covering shell 21, which is greater than the probability of the pressure relief portion 2111 rupturing and performing directional pressure relief, thereby causing the directional pressure relief failure of the pressure relief portion 2111.

[0155] Similarly, the battery pack 20 and the box body 10 are connected by the adhesive layer 12. When thermal runaway occurs in the battery pack 20, the force generated by the high-pressure gas fire flow will push the U-shaped covering shell 21 to have a movement trend of separating from the adhesive layer 12. When the bonding force corresponding to the bonding strength of the adhesive layer 12 is less than the force, the U-shaped covering shell 21 will separate from the adhesive layer 12, which will also cause the directional pressure relief of the pressure relief part 2111 to fail.

[0156] Based on this, the present application makes the shear strength of the connection part 231 greater than the first preset value, the first preset value is greater than or equal to 0.1Mpa, and the bonding strength of the glue layer 12 is greater than the second preset value, the second preset value is greater than or equal to 1Mpa, so that the connection strength between the connection part 231 and the U-shaped covering shell 21 and the shear strength of the connection part 231 itself can be greater than the structural strength of the pressure relief part 2111. At the same time, the bonding force generated by the bonding strength of the glue layer 12 can be greater than the force of the U-shaped covering shell 21 when thermal runaway occurs inside the battery pack 20, so as to ensure the connection stability between the connection part 231 and the U-shaped covering shell 21 and the connection stability between the U-shaped covering shell 21 and the box body 10 when directional pressure relief is performed through the pressure relief part 2111, reduce the probability of connection failure between the connection part 231 and the U-shaped covering shell 21 and connection failure between the box body 10 and the battery pack 20, and improve the reliability and stability of directional pressure relief.

[0157] It should be pointed out that the U-shaped covering shell 21 can be packaged with the soft-pack battery cell 22 arranged therein and the busbar brackets 23 located at both ends thereof, and after packaging, at least one side of the U-shaped covering shell 21 is bonded and fixed to the box body 10 by the adhesive layer 12. When the battery pack 20 is subjected to thermal runaway inside, the thermal runaway high-pressure gas and fire flow pushes the U-shaped covering shell 21 to generate a force to separate from the adhesive layer 12. Therefore, the bonding strength of the adhesive layer 12 needs to be no less than 1Mpa, so that the bonding force that the adhesive layer 12 can provide is greater than the thermal runaway force borne by the U-shaped covering shell 21. Similarly, the connecting portion 231 is used to connect to the U-shaped covering shell 21, and the force borne by the high-pressure gas and fire flow is mainly characterized by a shear force that causes the connecting portion 231 to undergo shear deformation. Therefore, the shear strength of the connecting portion 231 needs to be no less than 0.1Mpa.

[0158] Among them, the internal environment of the box 10 can be simulated, that is, a simulated box 10 is set up, and a battery pack 20 is arranged inside it, and thermal runaway occurs inside the battery pack 20 (such as: short-circuiting adjacent soft-pack battery cells 22 to trigger it), and then connecting parts 231 with different shear strengths are selected to obtain a first preset value through multiple tests; or adhesive layers 12 with different bonding strengths are selected to connect the battery pack 20 and the box 10, so as to obtain a second preset value through multiple tests. Of course, the first preset value and the second preset value can also be obtained through simulation analysis, or a pressure gauge and a tension gauge can be set up to measure the local force, and the first preset value and the second preset value can be further converted.

[0159] According to the battery device 100 of the embodiment of the present application, by making the shear strength of the connecting portion 231 greater than a first preset value and the bonding strength of the adhesive layer 12 greater than a second preset value, when thermal runaway occurs inside the battery pack 20, the pressure relief portion 2111 can be preferentially ruptured to provide directional pressure relief. During the directional pressure relief process, the probability of connection failure between the connecting portion 231 and the 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 the directional pressure relief, thereby improving the reliability of the battery device 100.

[0160] Combine Figure 3 、 Figure 6 、 Figure 9 、 Figure 11 as well as Figure 12 As shown, according to some embodiments of the present application, the U-shaped covering 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, the bus bracket 23 is located at both ends of the length of the U-shaped covering shell 21, and the connecting portion 231 is connected to the first plate 211 and / or the second plate 212.

[0161] Specifically, the first plate 211 is located at the top of multiple soft-pack battery cells 22 and covers the soft-pack battery cells 22 at the top of the soft-pack battery cells 22. A pressure relief portion 2111 can be formed on at least the circumferential surface 2212 of the soft-pack battery cells 22 at the top. The pressure relief portion 2111 is arranged corresponding to the pressure relief portion 2111 to achieve directional pressure relief, and the U-shaped covering shell 21 is provided with a bus bracket 23 at both ends of the length (the two ends of the length of the soft-pack battery cells 22). The bus bracket 23 can be connected to the first plate 211, the bus bracket 23 can also be connected to the second plate 212, or the bus bracket 23 is connected to the first plate 211 and the second plate 212 at the same time.

[0162] In this way, the connection portion 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 cover 21 , thereby improving the directional pressure relief stability and the reliability of the battery device 100 .

[0163] It is understood that in the embodiment of the present application, the connection portion 231 and the first plate 211 and / or the second plate 212 can be constructed in a variety of connection forms such as plug-in fit, welding fit or snap fit to achieve a stable and reliable connection. Figure 3 、 Figure 4 as well as Figure 5 The connection structure between the connection portion 231 of the present application and the first plate 211 and / or the second plate 212 is specifically described using three specific embodiments. The following three specific embodiments are merely illustrative descriptions to facilitate those skilled in the art to understand the technical solution of the present application, rather than an exhaustive list of feasible embodiments of the present application.

[0164] First embodiment:

[0165] like Figure 3 、 Figure 4 as well as Figure 5 As shown, in the first embodiment, the connecting portion 231 includes a plug-in column, and the connecting portion 231 is inserted into a slot formed on the first plate 211 and / or the second plate 212 .

[0166] Specifically, slots are provided at the ends of the first plate 211 and / or the second plate 212, and the connecting portion 231 includes a plug-in group, or the connecting portion 231 includes a slot, and plug-in columns are provided on the first plate 211 and / or the second plate 212, and the plug-in columns are inserted into the slots.

[0167] Thus, the bus bracket 23 and the U-shaped covering shell 21 can be plugged in and fastened together, which can improve the connection strength while reducing the difficulty of assembly and improving the assembly efficiency.

[0168] Furthermore, the orthographic projection size of the plug-in post toward the slot is larger than the opening size of the slot, so that the plug-in post and the slot are interference fit.

[0169] In which, in an embodiment in which both the first plate 211 and the second plate 212 are connected to the connecting portion 231, the slot may be an L-shaped slot. In an embodiment in which the first plate 211 or the second plate 212 is connected to the connecting portion 231, the slot may include a straight slot, and the opening size of the slot is L1. The sum of the thickness dimensions of the ends or plug-in columns of the first plate 211 and / or the second plate 212 that cooperate 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 constructed 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 improving the reliability of the battery device 100.

[0170] It should be pointed out that the projection size of the plug-in post toward the slot is smaller than the opening size of the slot so as to achieve an interference fit. In the embodiment where the plug-in post is round, the slot is also round, and the diameter of the slot is smaller than the diameter of the plug-in group. In the embodiment where the plug-in post is square, the slot is also square, and at least one of the length and width dimensions of the plug-in group is larger than the length and width dimensions of the plug-in post.

[0171] According to some embodiments of the present application, the projection size of the plug-in post toward the slot is larger than the opening size by 0.2 mm to 1 mm.

[0172] Table 1

[0173]

[0174] It should be noted that Table 1 is a comparison table of the difference between the projection size and the opening size and the shear strength of the connection part.

[0175] That is to say, it can be seen from Table 1 that in the first embodiment, the interference fit size between the plug-in post and the slot is not less than 0.2mm, which can improve the connection reliability and stability of the plug-in post and the slot, and avoid insufficient connection strength between the bus bracket 23 and the U-shaped covering shell 21 due to the interference amount being within the tolerance range. The interference fit size between the plug-in post and the slot is not greater than 1mm, which can reduce the difficulty of assembly and the probability of structural damage to the plug-in post during the assembly process, thereby extending the service life of the bus bracket 23.

[0176] Second embodiment:

[0177] like Figure 6 、 Figure 7 and Figure 8 As shown, in the second embodiment, the connecting portion 231 includes a lap plate, and the lap plate is connected to the first plate 211 and / or the second plate 212 .

[0178] Specifically, in an embodiment where the connecting portion 231 includes a lap plate, the connecting portion 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. This can also improve the connection strength between the connecting portion 231 and the U-shaped covering shell 21, thereby improving the directional pressure relief stability and improving the reliability of the battery device 100.

[0179] It can be understood 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 and the first plate 211 and the second plate 212 is lower, the welding strength is higher, and the sealing effect after welding is better.

[0180] According to some embodiments of the present application, the overlap size between the overlap plate and the first plate 211 and / or the second plate 212 is 1 mm-5 mm.

[0181] Table 2

[0182]

[0183] It should be noted that Table 2 is a comparison table of lap size and shear strength of the connection.

[0184] That is, as can be seen from Table 2, in the second embodiment, the overlap size is set to be no less than 1 mm, which can improve the connection strength between the connection portion 231 and the U-shaped covering shell 21 and reduce the probability of cold welding, poor welding, and insufficient bonding strength. The overlap size is set to be no more than 5 mm. Under the premise of ensuring the connection strength, the space occupied by the connection portion 231 can also be reduced to take into account the energy density of the battery pack 20.

[0185] According to some embodiments of the present application, the lap plate is fixed to the first plate 211 and / or the second plate 212 by adhesive bonding, welding or screwing.

[0186] Specifically, the ends of the first plate 211 and the second plate 212 are overlapped with the overlap plate, or the ends of the first plate 211 and the second plate 212 form an overlap portion whose thickness is less than the thickness of the first plate 211 and the second plate 212 themselves, and the overlap portion is overlapped with the overlap plate to make the outer surface of the battery pack 20 smoother.

[0187] Among them, structural adhesive can be set in the overlapping matching area between the overlapping plate and the first plate 211 and the second plate 212 to achieve adhesive fixation of the connecting part 231 and the U-shaped covering shell 21. The overlapping matching area can also be welded or screwed to effectively improve the connection strength between the U-shaped covering shell 21 and the bus bracket 23.

[0188] It should be pointed out that in the embodiment where the lap plate is fixed to the first plate 211 and the second plate 212 by screwing, threaded holes can be provided on the lap plate or the first plate 211 and the second plate 212, and the fasteners used for threaded fastening are constructed as countersunk screws or countersunk studs to make the outer surface of the second plate 212 smoother.

[0189] Third embodiment:

[0190] like Figure 9 As shown, in the third embodiment, according to some embodiments of the present application, the connecting portion 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 engagement with the first snap-fit ​​structure.

[0191] Specifically, the first snap-fit ​​structure can be constructed as a snap or a slot, and the corresponding second snap-fit ​​structure can be constructed as a slot or a snap, so as to achieve the fixation of the bus bracket 23 and the U-shaped covering shell 21 through the snap-fit ​​cooperation between the first snap-fit ​​structure and the second snap-fit ​​structure, and achieve the same technical effect as the above-mentioned first and second embodiments, which will not be repeated here.

[0192] According to some embodiments of the present application, the bus bracket 23 also 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 the connecting portion 231 is located on at least one side edge of the insulating body 232, and 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 passes through the insulating body 232, the first groove 2321 is connected to the second groove 2322, and the first groove 2321 is suitable for accommodating the pole ear, and the second groove 2322 is suitable for accommodating the bus bar body electrically connected to the pole ear.

[0193] Specifically, the insulating body 232 can be constructed as an insulating structure such as a plastic part or a rubber part, the connecting portion 231 can be integrally formed with the insulating body 232, or the connecting portion 231 can be constructed as a metal insert and embedded in the insulating body 232. By using the connecting portion 231 constructed as a metal insert, the connection strength and reliability between the bus bracket 23 and the U-shaped covering shell 21 can be improved. At the same time, the insulating body 232 can be used to separate the connecting portion 231 from the tab, bus bar, etc., which can also reduce the probability of short circuit in the battery pack 20 and improve the reliability of the battery pack 20.

[0194] At the same time, by providing a sealing portion 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 provision of the first groove 2321 and the second groove 2322 on the insulating body 232 can make the electrical connection between the busbar body and the tab less difficult, and the electrical connection between multiple soft-pack battery cells 22 and the electrical connection between adjacent battery packs 20 less difficult.

[0195] It should be pointed out that when a single soft-pack battery cell 22 experiences thermal runaway, high-temperature and high-pressure gas will be generated inside the soft-pack battery cell 22, and a certain amount of solid particles, liquids, etc. will be entrained to form a high-temperature gas and fire flow. The temperature and pressure of the high-temperature gas and fire flow generated by the soft-pack battery cell 22 are strongly correlated with the energy density of the soft-pack battery cell 22. That is, the greater the energy density, the greater the force acting on the connection area between the U-shaped covering shell 21 and the bus bracket 23 during the pressure release process, and the higher the requirements for the connection strength of the connection area between the U-shaped covering shell 21 and the bus bracket 23, the shear strength of the connection part 231 itself, and the bonding strength of the glue layer 12.

[0196] Based on this, the present application defines the energy density of the soft-pack battery cell 22, the shear strength of the connecting portion 231, and the bonding strength of the adhesive layer 12 as follows:

[0197] 1. When the energy density of the soft-pack battery cell 22 is 450 Wh / L to 600 Wh / L, the connection strength between the connection portion 231 and the U-shaped cover 21 is 0.1 MPa to 0.2 MPa, the shear strength of the connection portion 231 is 0.1 MPa to 0.2 MPa, and the adhesive strength of the adhesive layer 12 is 1 MPa to 2.5 MPa;

[0198] 2. When the energy density of the soft-pack battery cell 22 is 600Wh / L-700Wh / L, the shear strength of the connecting portion 231 is 0.2Mpa-0.3Mpa, and the bonding strength of the adhesive layer 12 is 2.5Mpa-5.5Mpa;

[0199] 3. When the energy density of the soft-pack battery cell 22 is greater than 700Wh / L, the shear strength of the connecting portion 231 is 0.3 MPa to 0.5 MPa, and the bonding strength of the adhesive layer 12 is 5.5 MPa to 10.5 MPa.

[0200] Specifically, when the energy density of the soft-pack battery cell 22 is less than 450 Wh / L, the pressure acting on the connection area between the connection portion 231 and the U-shaped cover shell 21 is small when thermal runaway occurs, the shear force borne by the connection portion 231 is small, and the tearing force borne by the adhesive layer 12 is small. The shear strength of the conventional connection portion 231 and the adhesion strength of the conventional adhesive layer 12 can meet the pressure bearing requirements of directional pressure relief. Therefore, this application does not make further restrictions on it. When the energy density of the soft-pack battery cell 22 is greater than or equal to 450Wh / L and less than 600 Wh / L, when thermal runaway occurs, the pressure acting on the connection area between the connection part 231 and the U-shaped covering shell 21 increases, and the shear force borne by the connection part 231 and the tearing force borne by the adhesive layer 12 increase accordingly. At this time, the shear strength of the conventional connection part 231 and the bonding force provided by the conventional adhesive layer 12 cannot meet the pressure bearing requirements of directional pressure relief, and the shear strength of the connection part 231 is greater than 0.1Mpa and less than or equal to 0.2Mpa, and the bonding strength of the adhesive layer 12 is greater than 1Mpa and less than or equal to 2.5Mpa. When the energy density of the soft-pack battery cell 22 is greater than or equal to 600Wh / L and less than 700 Wh / L, when thermal runaway occurs, the pressure acting on the connection area between the connection part 231 and the U-shaped cover shell 21 increases again, and the shear force borne by the connection part 231 and the tearing force borne by the adhesive layer 12 increase again. At this time, the shear strength of the conventional connection part 231 and the adhesive force provided by the conventional adhesive layer 12 cannot meet the pressure bearing requirements of directional pressure relief, and the shear strength of the connection part 231 is greater than 0.2Mpa and less than or equal to 0.3Mpa, and the adhesive strength of the adhesive layer 12 is greater than 2.5Mpa and less than or equal to 5.5Mpa. When the energy of the soft-pack battery cell 22 is less than 100W, the pressure of the connection part 231 and the peeling force of the adhesive layer 12 are increased again. The mass density is greater than or equal to 700Wh / L. When thermal runaway occurs, the pressure acting on the connection area between the connection part 231 and the U-shaped covering shell 21 is further increased, and the shear force borne by the connection part 231 and the tearing force borne by the adhesive layer 12 are further increased. At this time, the shear strength of the conventional connection part 231 and the bonding force provided by the conventional adhesive layer 12 cannot meet the pressure-bearing requirements of directional pressure relief. The shear strength of the connection part 231 only needs to be greater than 0.3Mpa and less than or equal to 0.5Mpa, and the bonding strength of the adhesive layer 12 only needs to be greater than 5.5Mpa and less than or equal to 10.5Mpa.

[0201] Therefore, based on the energy density, the shear strength of the connection part 231 can be reasonably set, which can avoid the connection strength between the connection part 231 and the U-shaped covering shell 21 being too low, and reduce the probability of failure of the connection part 231 to ensure that the connection strength between the connection 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 to avoid structural redundancy and reduce costs. At the same time, the bonding strength of the glue layer 12 can be reasonably set, which can also reduce the connection failure between the battery pack 20 and the box body 10, especially the probability of connection failure between the U-shaped covering shell 21 and the box body 10, to meet the directional pressure relief requirements.

[0202] It should be pointed out that the shear strength of the connection portion 231 and the bonding strength of the adhesive layer 12 can be measured by simulating the internal environment of the box 10 and performing an inflation test, that is, a test sample of the same material and thickness as the U-shaped covering shell 21 is selected and connected to the bus bracket 23 to form a closed space, and air is inflated into the closed space. The pressure in the closed space is recorded when the connection portion 231 is disengaged from the U-shaped covering shell 21, or when the adhesive layer 12 is disengaged from the U-shaped covering shell 21, and the bonding strength of the adhesive layer 12 and the bus bracket 23 are calculated by converting the pressure. The shear strength of the connection portion 231 of the frame 23 can, of course, also be measured by other destructive tests to measure the shear strength of the connection portion 231 and the bonding strength of the adhesive layer 12. For example, a tensile test can be used when the connection portion 231 and the U-shaped covering shell 21 are glued, welded, screwed, or clamped. In the embodiment where the connection portion 231 and the U-shaped covering shell 21 are glued or welded, a shear test can also be used to measure the shear strength. Similarly, the bonding strength between the adhesive layer 12 and the U-shaped covering shell 21 can also be obtained through a tensile test.

[0203] For example, Table 3 is a comparison table of runaway temperature, internal pressure, and adhesive layer bonding strength at different energy densities for a specific product of a soft-pack battery cell 22 with a length of 355 mm, a height of 123 mm, and a width of 13.8 mm.

[0204] Table 3

[0205]

[0206] As shown in the table above, the soft-pack battery cell 22 of the embodiment of the present 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 a bonding 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 450 Wh / L to 600 Wh / L (greater than or equal to 450 Wh / L and less than 600 Wh / L). 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), the shear strength is 0.2 MPa to 0.3 MPa (greater than or equal to 0.12 MPa and less than 0.3 MPa), and 2.5 MPa to 5.5 MPa (greater than or equal to 2.5 MPa and less than 5.5 MPa) when the energy density is in the range of 700 Wh / L (greater than or equal to 700 Wh / L). Wh / L) or above, the shear strength is 0.3Mpa~0.5Mpa (greater than or equal to 0.3 Mpa and less than 0.5 Mpa), and the bonding strength is 2.5Mpa~10.5Mpa (greater than or equal to 2.5Mpa and less than 10.5 Mpa). The shear strength can be higher than the internal pressure, and the bonding force corresponding to the bonding strength can be greater than the tensile force to ensure the reliability and stability of the connection between the connecting portion 231 and the U-shaped covering shell 21, and the battery pack 20 and the box body 10.

[0207] like Figure 2 As shown, the battery device 100 includes: a box 10 and a battery pack 20, there is at least one battery pack 20, and the battery pack 20 includes: at least one soft-pack battery cell 22 in the above embodiment and a U-shaped covering shell 21, and at least one side surface of the U-shaped covering shell 21 has a weak portion 2213.

[0208] In which, a accommodating space is formed in the box body 10, and one or more battery packs 20 are arranged in the accommodating space. One or more soft-pack battery cells 22 are arranged inside the U-shaped covering shell 21 of each battery pack 20, and the soft-pack battery cell 22 is constructed as the above-mentioned soft-pack battery cell 22 using the flexible shell 221.

[0209] The U-shaped covering shell 21 is used to cover at least at least one of the multiple circumferential surfaces 2212 and two side surfaces 2211 of the soft-pack battery cell 22, and 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 of the U-shaped covering shell 21 (such as the first plate 211), such that the pressure relief portion 2111 is opposite to the weak portion 2213, or the pressure relief portion 2111 is located on the first surface of the U-shaped covering shell 21, and the weak portion 2213 is opposite to the second surface of the U-shaped covering shell 21, and the first surface is adjacent to the second surface.

[0210] Therefore, by providing a pressure relief portion 2111 on the U-shaped covering shell 21 to cooperate with the weak portion 2213, when thermal runaway occurs in the soft-pack battery cell 22, the high-temperature gas and fire flow discharged through the pressure relief area (weak portion 2213) can be further released outward through the pressure relief portion 2111. Through the cooperation between the weak portion 2213 and the pressure relief portion 2111, the directional discharge of the high-temperature gas and fire flow is achieved, thereby improving the reliability of the battery device 100.

[0211] According to some embodiments of the present application, the U-shaped covering shell 21 includes a first plate 211 and second plates 212 located on both sides of the first plate 211 . A pressure relief portion 2111 is formed on the first plate 211 , and the weak portion 2213 is at least partially opposite to the pressure relief portion 2111 .

[0212] Specifically, the first plate 211 and the second plates 212 located on both sides of the first plate 211 define a U-shaped covering shell 21 that is generally U-shaped, so that the first plate 211 of the U-shaped covering shell 21 can be opposite to a circumferential surface 2212 of the soft-pack battery cell 22, and 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.

[0213] It should be noted that the weak portion 2213 is at least partially opposite to the pressure relief portion 2111 , which means that the weak portion 2213 formed on the circumferential surface 2212 is projected toward the first plate 211 , and the projection contour at least partially overlaps with the contour of the pressure relief portion 2111 .

[0214] In this way, on the one hand, the gas and fire flow generated after the thermal runaway of the soft-pack battery cell 22 can be discharged in a direction and orderly to reduce damage, especially secondary damage. On the other hand, the communication path between the pressure relief area and the pressure relief part 2111 is shorter, which can achieve rapid discharge. At the same time, the gas and fire flow stays in the U-shaped covering shell 21 for a shorter time, which has less impact on other soft-pack battery cells 22 around the thermal runaway soft-pack battery cell 22, and can further reduce the spread speed of thermal runaway, thereby improving the reliability of the battery pack 20 and the battery device 100.

[0215] According to some embodiments of the present application, the second plate 212 is opposite to the side surface 2211 , and a projected contour area of ​​the second plate 212 facing the side surface 2211 of the flexible housing 221 is smaller than or equal to an area of ​​the side surface 2211 .

[0216] Specifically, the circumferential surface 2212 is defined to include a first surface and a second surface opposite thereto, the first surface is opposite to the first plate 211, the second surface is arranged away from the first plate 211, and the second surface is used to connect to the box body 10, the two sides of the first surface and the second surface are respectively the two side surfaces 2211 of the soft-pack battery cell 22, the two ends of the first surface and the second surface are respectively the other two circumferential surfaces 2212 of the soft-pack battery cell 22, and the second plate 212 is opposite to the side surface 2211 to achieve the limitation of the soft-pack battery cell 22 in the direction of the second plate 212, and the area size of the surface of the second plate 212 opposite to the side surface 2211 can be less than or equal to the area size of the side surface 2211.

[0217] That is, in some embodiments, the size of the second plate 212 is consistent with the size of the side 2211, and in other embodiments, the size of the second plate 212 is smaller than the size of the side 2211. On the one hand, it can avoid the second plate 212 being too large, resulting in the second side being unable to connect to the box 10, and can improve the fixation stability and reliability of the battery pack 20 in the box 10. On the other hand, the material used for the second plate 212 can be less, and the material cost of the battery pack 20 and the battery device 100 can also be reduced.

[0218] like Figure 3 、 Figure 6 as well as Figure 9 As shown, according to some embodiments of the present application, the first plate 211 is spaced apart from a side of the circumferential surface 2212 having the weak portion 2213 to define an exhaust channel a.

[0219] In this way, the high-temperature gas and fire flow generated after the weak part 2213 ruptures can be discharged to the exhaust channel a first, and after preliminary buffering through the exhaust channel a, it is discharged through the pressure relief part 2111, which can reduce the pressure of the high-temperature gas and fire flow after flowing out of the pressure relief part 2111, thereby reducing the impact and damage after the thermal runaway of the soft-pack battery cell 22.

[0220] According to some embodiments of the present application, the first plate 211 is configured as a straight plate or a curved plate.

[0221] That is, in some embodiments, the first plate 211 is configured as a straight plate, and in other embodiments, the first plate 211 is configured as a curved plate.

[0222] According to some embodiments of the present application, there are multiple pressure relief portions 2111 , and the multiple pressure relief portions 2111 are spaced apart in the length direction and / or width direction of the first plate 211 .

[0223] Thus, the multiple weak parts 2213 on each soft-pack battery cell 22 can have a corresponding pressure relief part 2111, so that the high-temperature gas and fire flow buffered by the exhaust channel a can be discharged directly through the corresponding pressure relief part 2111, thereby increasing the discharge speed and reducing the residence time of the high-temperature gas and fire flow in the exhaust channel a during the discharge process, so as to reduce the spread speed of thermal runaway between adjacent soft-pack battery cells 22 in the battery pack 20 and improve the reliability of the battery pack 20.

[0224] According to some embodiments of the present application, the U-shaped covering shell 21 is constructed as an aluminum shell or a stainless steel shell.

[0225] It can be understood that in some embodiments, the U-shaped covering shell 21 is constructed as an aluminum shell, and in other embodiments, the U-shaped covering shell 21 is constructed as a stainless steel shell, so that the temperature resistance and structural strength of the U-shaped covering shell 21 are much higher than those of the 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 outside the soft-pack battery cell 22, the structural strength of the battery pack 20 can be improved, and the thermal runaway propagation speed between adjacent battery packs 20 can be reduced, thereby improving the reliability of the battery device 100.

[0226] Combine Figure 12 As shown, according to some embodiments of the present application, the box body 10 has a bottom plate 11 , and the bottom plate 11 is connected to the soft-pack battery cell 22 through an adhesive layer 12 .

[0227] Specifically, the bottom plate 11 of the box body 10 is connected to the second surface of the soft-pack battery cell 22 via the adhesive layer 12 to fix the battery pack 20 on the box body 10 and improve the fixing stability and reliability of the battery pack 20.

[0228] Of course, in some embodiments, the adhesive layer 12 is also used to connect and fix the bottom plate 11 and the second plate 212 .

[0229] Combine Figure 12 As shown, according to some embodiments of the present application, 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 .

[0230] In some embodiments, the bottom plate 11 of the box body 10 is formed as a cold plate, and the cold plate is connected to the soft-pack battery cell 22 through the 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 the adhesive layer 12.

[0231] That is, the adhesive layer 12 is constructed as structural adhesive, and the bottom plate 11 provided with a cold plate is connected to the soft-pack battery cell 22. On the premise of ensuring that the battery pack 20 is stably and reliably fixed in the box 10, the temperature of the battery pack 20 can also be regulated by the cold plate, so that the battery pack 20 can operate at a suitable temperature, thereby improving the operating stability and reliability of the battery pack 20, reducing the probability of overheating of the battery pack 20, and reducing the probability of thermal runaway of the battery pack 20, thereby improving the reliability of the battery pack 20 and even the battery device 100.

[0232] like Figure 12 As shown, according to some embodiments of the present application, the glue layer 12 includes: a glue layer body 121 and a glue overflow portion 122, the glue overflow portion 122 is located on the side of the glue layer body 121 facing the multiple soft-pack battery cells 22, and is located between adjacent soft-pack battery cells 22, and / or between the soft-pack battery cells 22 and the second plate 212.

[0233] That is to say, when the structural adhesive is used to connect and fix the soft-pack battery cells 22 to the cold plate, at least part of the glue layer 12 overflows between adjacent soft-pack battery cells 22 and / or between the second plate 212 and the soft-pack battery cells 22, and forms an overflow glue portion 122. The provision of the overflow glue portion 122 can not only increase the area between the glue layer 12 and the soft-pack battery cells 22, and the glue layer 12 and the second plate 212, so as to improve the fixation stability and reliability of the battery pack 20 on the box 10, but also fill the gaps between adjacent soft-pack battery cells 22 and between the soft-pack battery cells 22 and the second plate 212 through the overflow glue portion 122, so as to achieve the limitation of the soft-pack battery cells 22 and the U-shaped covering shell 21, reduce the movement of the battery pack 20 in the box 10, and reduce the movement of the soft-pack battery cells 22 in the U-shaped covering shell 21.

[0234] According to some embodiments of the present 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.

[0235] That is, in some embodiments, the soft-pack battery cell 22 is configured as a lithium iron phosphate battery, in some embodiments, the soft-pack battery cell 22 is configured as a ternary lithium battery cell, and in some embodiments, the soft-pack battery cell 22 is configured as a solid-state battery cell.

[0236] The solid-state battery cell may be, but is not limited to, a polymer solid-state battery cell, an oxide solid-state battery cell, a sulfide solid-state battery cell, a halide solid-state battery cell, etc. The solid-state battery cell may also be a semi-solid-state battery cell or a fully solid-state battery cell.

[0237] In the above technical solution, in the embodiment of the present application constructed as a lithium iron phosphate battery cell, the reliability of the soft-pack battery cell can be improved and the cycle life of the soft-pack battery cell can be extended. In the embodiment of the present application constructed as a ternary lithium battery cell, the energy density of the soft-pack battery cell can be improved and the cruising range can be increased. In the embodiment of the present application constructed as a solid-state soft-pack battery cell, not only the energy density can be improved, but also the reliability can be improved.

[0238] According to some embodiments of the present application, when the soft-pack battery cell 22 is a lithium iron phosphate (LiFeO4) battery cell, the ratio of the positive electrode active material, the positive electrode binder, and the positive electrode conductive agent in the positive electrode material of the soft-pack battery cell 22 is 96: (1-3): (1-3); when the soft-pack battery cell 22 is a ternary lithium battery cell, and the ratio of the positive electrode active material, the positive electrode binder, and the positive electrode conductive agent in the positive electrode material of the soft-pack battery cell 22 is 96: (2-3): (1-2).

[0239] It can be understood that when the soft-pack battery cell 22 is a lithium iron phosphate battery cell, in the positive electrode material of the soft-pack battery cell 22, 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.).

[0240] For example, when the soft-pack battery cell 22 is a lithium iron phosphate battery cell, the positive electrode active material is LFP (which can be 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. That is, out of 100 parts by weight of the total positive electrode active material, LFP accounts for 96 parts, PVDF accounts for 2 parts, and conductive carbon black also accounts for 2 parts. The weight of the positive electrode active material can be expressed in grams.

[0241] When the soft-pack battery cell 22 is a ternary battery cell, the positive electrode material of the soft-pack battery cell 22 comprises 96 parts by weight of the positive electrode active material, 2-3 parts by weight of the binder (e.g., including but not limited to 2, 2.2, 2.5, 2.8, 3, etc.), and 1-2 parts by weight of the conductive agent (e.g., including but not limited to 1, 1.2, 1.5, 1.8, 2, etc.). The ternary battery cell may be, but is not limited to, a lithium nickel cobalt manganese oxide (LNO)-based battery, a lithium nickel cobalt aluminum oxide (LNO)-based battery, or the like.

[0242] For example, the ternary material of the ternary battery cell can be eight series LiNi 0.8 Co 0.1 Mn 0.1 O2, the weight ratio of the positive electrode active material, binder and conductive agent is 96:2.5:1.5, that is, the total weight of the positive electrode material is divided into 100 parts, the eight series LiNi 0.8 Co 0.1 Mn 0.1 O2 accounts for 96 parts, the binder accounts for 2.5 parts, and the conductive agent accounts for 1.5 parts.

[0243] In the above technical solution, when the soft-pack battery cell 22 is a lithium iron phosphate battery cell, a high proportion of positive electrode active material means that more substances capable of undergoing electrochemical reactions can be accommodated within the limited electrode assembly, which is beneficial for increasing the capacity and energy density of the battery device 100. This allows the lithium iron phosphate battery cell to output a higher amount of electricity while being relatively small in size and weight, meeting application scenarios with certain requirements for energy density. The use of the binder and conductive agent within the above ranges can reduce the cost of auxiliary materials, thereby reducing the overall cost of the battery device 100. When the soft-pack battery cell 22 is a ternary battery cell, due to the relatively complex structure and surface properties of the ternary material itself, the use of the above-mentioned proportions of positive electrode active material, binder, and conductive agent is beneficial for ensuring good bonding between the 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, reducing the risk of active material shedding and electrode pulverization during charging and discharging, and extending the cycle life of the battery device 100.

[0244] The present application proposes an electric device 200 , comprising: the battery device 100 in the above embodiment.

[0245] Furthermore, if Figure 1 As shown, the electrical equipment 200 can be a vehicle, and the battery device 100 can be integrated on the chassis of the vehicle, that is, the body structure is a split body, the upper body and the integrated intelligent chassis are assembled, and the battery device 100 forms a part of the integrated intelligent chassis, and thus the top plate of the box body 10 can also participate in defining the body floor, which can save meaningless multi-layer plate stacking, reduce material costs, and make the space occupied by the chassis more reasonable. The space inside the chassis for accommodating the battery device 100 is larger and the energy density is higher.

[0246] It is understandable that the electrical device 200 is configured as a vehicle, that is, the vehicle uses the above-mentioned battery device 100. The battery device 100 has a higher energy density and higher reliability, which can improve the vehicle's driving safety while increasing the vehicle's cruising range.

[0247] Other structures and operations of the soft-pack battery cell 22 , the battery device 100 , and the electrical device 200 according to the embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0248] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative use of the above terms does 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 any one or more embodiments or examples.

[0249] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery device (100), characterized in that: include: Box (10); A battery pack (20), comprising a U-shaped covering shell (21), a plurality of soft-pack battery cells (22) and a busbar support (23); the U-shaped covering shell (21) and the box body (10) are bonded together via an adhesive layer (12); the busbar support (23) is arranged on the U-shaped covering shell (21) and connected to the U-shaped covering shell (21) via a connecting portion (231); the U-shaped covering shell (21), the box body (10) and the busbar support (23) together form a storage space; the plurality of soft-pack battery cells (22) are arranged in the storage space and are electrically connected via the busbar support (23); The U-shaped covering shell (21) has a pressure relief portion (2111), the shear strength of the connecting portion (231) is greater than a first preset value, the first preset value is greater than or equal to 0.1 MPa, and the bonding strength of the adhesive layer (12) is greater than a second preset value, the second preset value is greater than or equal to 1 MPa.

2. The battery device (100) according to claim 1, characterized in that: The U-shaped covering shell (21) comprises: a first plate (211) forming the pressure relief portion (2111) and second plates (212) located on both sides of the first plate (211); the bus bracket (23) is located at both ends of the length of the U-shaped covering shell (21), and the connecting portion (231) is connected to the first plate (211) and / or the second plate (212).

3. The battery device (100) according to claim 2, characterized in that: The connecting portion (231) comprises a plug-in column, and the connecting portion (231) 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, characterized in that: The orthographic projection size of the plug-in column toward the slot is larger than the opening size of the slot, so that the plug-in column and the slot are interference-fitted.

5. The battery device (100) according to claim 4, characterized in that: The projection size of the plug-in column toward the slot is larger than the opening size by 0.2 mm to 1 mm.

6. The battery device (100) according to claim 2, characterized in that: The connecting portion (231) comprises a lap plate, and the lap plate is connected to the first plate (211) and / or the second plate (212).

7. The battery device (100) according to claim 6, characterized in that: The overlapping dimension between the overlapping plate and the first plate (211), and / or the second plate (212) is 1 mm to 5 mm.

8. The battery device (100) according to claim 6, characterized in that: The lap 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 2, characterized in that: The connecting portion (231) comprises a first clamping structure, and a second clamping structure that is clamped and matched with the first clamping structure is formed at the length end of the first plate (211) and / or the second plate (212).

10. The battery device (100) according to claim 1, characterized in that: The busbar support (23) comprises: an insulating body (232) and a sealing portion (233), wherein 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), and a first groove (2321) and a second groove (2322) are formed on the insulating body (232), wherein the first groove (2321) is located on a side surface of the insulating body (232) facing the soft-pack battery cell (22), and the second groove (2322) is located on an adjacent side surface of the insulating body (232) and passes through the insulating body (232), the first groove (2321) is communicated with the second groove (2322), and the first groove (2321) is suitable for accommodating a tab, and the second groove (2322) is suitable for accommodating a busbar body electrically connected to the tab.

11. The battery device (100) according to claim 10, characterized in that: When the energy density of the soft-pack battery cell (22) is 450 Wh / L to 600 Wh / L, the shear strength of the connecting portion (231) is 0.1 MPa to 0.2 MPa, and the bonding strength of the adhesive layer (12) is 1 MPa to 2.5 MPa; When the energy density of the soft-pack battery cell (22) is 600 Wh / L to 700 Wh / L, the shear strength of the connecting portion (231) is 0.2 MPa to 0.3 MPa, and the bonding strength of the adhesive layer (12) is 2.5 MPa to 5.5 MPa; When the energy density of the soft-pack battery cell (22) is greater than 700Wh / L, the shear strength of the connecting portion (231) is 0.3Mpa to 0.5Mpa, and the bonding strength of the adhesive layer (12) is 5.5Mpa to 10.5Mpa.

12. The battery device (100) according to claim 2, characterized in that: There are a plurality of pressure relief portions (2111), and the plurality of pressure relief portions (2111) are arranged at intervals in the length direction and / or width direction of the first plate (211).

13. The battery device (100) according to claim 2, characterized in that: The first plate (211) is configured as a straight plate or a curved plate.

14. The battery device (100) according to claim 2, characterized in that: The soft-pack battery cell (22) comprises: a flexible shell (221) and an electrode assembly (222) arranged in the flexible shell (221); the flexible shell (221) has a side surface (2211) opposite to a 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, characterized in that: The projection contour area of ​​the second plate (212) facing the side surface (2211) of the flexible housing (221) is smaller than or equal to the area of ​​the side surface (2211).

16. The battery device (100) according to claim 14, characterized in that: 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, characterized in that: The first plate (211) is spaced apart from a side of the circumferential surface (2212) having the weak portion (2213) to define an exhaust passage (a).

18. The battery device (100) according to claim 1, characterized in that: The U-shaped covering shell (21) is constructed as an aluminum shell or a stainless steel shell.

19. The battery device (100) according to claim 2, characterized in that: An end surface of the soft-pack battery cell (22) that is away from the first plate (211) is connected to the box body (10) via the adhesive layer (12).

20. The battery device (100) according to claim 19, characterized in that: The box body (10) has a bottom plate (11), and the bottom plate (11) is connected to the soft-pack battery cell (22) via the adhesive layer (12).

21. The battery device (100) according to claim 20, characterized in that: The bottom plate (11) comprises 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, characterized in that: The glue layer (12) comprises: a glue layer body (121) and a glue overflow portion (122), wherein the glue overflow portion (122) is located on a side of the glue layer body (121) facing the plurality of soft-pack battery cells (22), and is located between adjacent soft-pack battery cells (22), and / or between the soft-pack battery cells (22) and the second plate (212).

23. The battery device (100) according to any one of claims 1 to 22, characterized in that: 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.

24. An electrical device (200), characterized in that: include: The battery device (100) according to any one of claims 1 to 23.

25. The electrical device (200) according to claim 24, characterized in that: The electrical equipment (200) is a vehicle.

26. The electrical device (200) according to claim 25, characterized in that: The battery device (100) is integrated into the chassis of the vehicle, and the top plate of the box (10) helps define the vehicle body floor.

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