Battery device and electric equipment

Abstract

The utility model relates to the technical field of batteries, and discloses a battery device and electric equipment, the battery device comprises a plurality of soft package battery monomers and a coating shell, the plurality of soft package battery monomers are sequentially stacked and electrically connected; the wrapping shell wraps the plurality of soft package battery monomers, and the wrapping shell is configured to restrain the plurality of soft package battery monomers from at least three directions; the strength of the coating shell is higher than that of the flexible shell of the soft package battery monomer; wherein the thickness of a plate body for constraining the plurality of soft package battery monomers by the coating shell is less than or equal to 5.2 mm and greater than or equal to 0.2 mm. Therefore, on one hand, the structural strength of the coating shell can be improved, and the probability that the coating shell is subjected to structural damage after being impacted by high-pressure gas fire flow is reduced, so that heat of the soft package battery monomers is diffused and concentrated in the coating shell, the probability of heat diffusion outside the coating shell is reduced, and the reliability of the battery device is improved; the energy density of the battery device can be considered, and the production cost of the battery device is reduced.

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 thermal protection between adjacent battery packs of the soft-pack battery device, which affects the further improvement of the reliability of the soft-pack battery device. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a battery device and an electrical device, the battery device has higher reliability and better resistance to thermal runaway.

[0004] In a first aspect, the present application provides a battery device, comprising: a plurality of soft-pack battery cells and a covering shell, wherein the plurality of soft-pack battery cells are stacked in sequence and electrically connected; the covering shell covers the outside of the plurality of soft-pack battery cells, and the covering shell is configured to constrain the plurality of soft-pack battery cells from at least three directions; the strength of the covering shell is higher than the strength of the flexible outer shell of the soft-pack battery cell; wherein the thickness of the plate body of the covering shell constraining the plurality of soft-pack battery cells is less than or equal to 5.2 mm and greater than or equal to 0.2 mm.

[0005] According to the battery device of the embodiment of the present application, by making the strength of the covering shell higher than the strength of the flexible shell and making the thickness size of the covering shell more reasonable, on the one hand, the structural strength of the covering shell can be improved, and the probability of structural damage to the covering shell after being impacted by the high-pressure gas and fire flow can be reduced, so that the heat diffusion of the soft-pack battery cell is concentrated inside the covering shell, and the probability of heat diffusion outside the covering shell is reduced, so as to improve the reliability of the battery device. On the other hand, the energy density of the battery device can be taken into account and the production cost of the battery device can be reduced.

[0006] According to some embodiments of the present application, the thickness of the plate body of the covering shell constraining the plurality of soft-pack battery cells is less than or equal to 3 mm and greater than or equal to 0.5 mm.

[0007] In the above technical solution, the thickness of the coating shell is not more than 3 mm to take into account the space occupied by the coating shell and improve the energy density of the battery device, and is not less than 0.5 mm to ensure that the structural strength of the coating shell can meet the use requirements. Under the impact of high-pressure gas and fire flow, the probability of structural damage to the coating shell is smaller, and the heat dissipation effect of the plate with a more reasonable thickness is better, which can improve heat concentration, reduce the probability of the coating shell melting due to heat, and improve the insulation effect of the coating shell against thermal runaway, so as to make the battery device more reliable.

[0008] According to some embodiments of the present application, the thickness of the plate body of the covering shell constraining the plurality of soft-pack battery cells is less than or equal to 1 mm and greater than or equal to 0.6 mm.

[0009] In the above technical solution, on the one hand, the thickness of the plate body is greater than 0.6 mm, which ensures the structural strength while taking into account the heat dissipation effect of the plate body and improving the heat concentration of the plate body to improve the insulation effect of thermal runaway and effectively delay the spread of thermal runaway to the outside. On the other hand, the thickness of the plate body is less than 1 mm, which can reduce the material cost of the coating shell to reduce the production cost and make the space occupied by the coating shell more reasonable, taking into account the energy density of the battery device.

[0010] According to some embodiments of the present application, the covering shell is an aluminum shell, and the thickness of the plate body of the covering shell that constrains multiple soft-pack battery cells is less than or equal to 1 mm and greater than or equal to 0.4 mm; or the covering shell is a stainless steel shell, and the thickness of the plate body of the covering shell that constrains multiple soft-pack battery cells is less than or equal to 1 mm and greater than or equal to 0.2 mm.

[0011] In the above technical solution, based on the covering shells of different materials, when the covering shell is constructed as an aluminum material, the minimum thickness of the plate body is made larger to reduce the probability of structural damage after heat concentration in the covering shell and improve reliability. When the covering shell is constructed as a stainless steel material, the minimum thickness of the plate body is made smaller, which can further improve the space occupied by the covering shell.

[0012] According to some embodiments of the present application, the covering shell includes a first plate, a second plate, and a third plate that are bent and connected in sequence, and the first plate and the third plate form openings on the side facing away from the second plate; the covering shell is connected to the box body of the battery device through the opening position; the first plate, the second plate, and the third plate respectively constrain multiple soft-pack battery cells along three directions.

[0013] In the above technical solution, the first plate and the third plate are arranged opposite to each other, and the second plate is located at one end on the same side of the first plate and the third plate, so that the other end on the same side of the first plate and the third plate defines an opening, and the opening position is used to connect with the box body, that is, the end surface of the first plate and the third plate on one side away from the second plate is connected to the box body, so that the soft-pack battery cell is constrained by the first plate, the second plate and the third plate on two opposite surfaces and one adjacent surface of the soft-pack battery cell respectively, while improving the constraining effect on the battery cell, the connection between the covering shell and the box body, and the connection between the soft-pack battery cell and the box body can be located on the same side, which can also reduce the difficulty of assembly and improve the assembly efficiency.

[0014] According to some embodiments of the present application, the first plate and the third plate constrain the plurality of soft-pack battery cells in opposite directions.

[0015] In the above technical solution, the first plate and the third plate are arranged opposite to each other, and the soft-pack battery cells are constrained in opposite directions by the first plate and the third plate arranged opposite to each other, so as to reduce the movement of the soft-pack battery cells and improve the fixation stability and reliability of the battery pack in the box.

[0016] Exemplarily, the first plate and the third plate can constrain and limit the soft-pack battery cells in the width direction of the soft-pack battery cells, and the width direction of the soft-pack battery cells can correspond to the width direction or length direction of the battery device, so that the soft-pack battery cells can be limited in the width or length direction of the battery device to reduce the movement of the battery pack relative to the box in the width direction or length direction of the battery device, thereby improving the stability and reliability of the battery device.

[0017] According to some embodiments of the present application, a direction in which the second plate constrains the plurality of soft-pack battery cells is perpendicular to a direction in which the first plate or the third plate constrains the plurality of soft-pack battery cells.

[0018] In the above technical solution, the second plate is connected to the first plate and the third plate on both sides of the first direction respectively to define an opening in the second direction, and the surface of the soft-pack battery cell on one side of the opening can be connected to the box body, and the first direction is perpendicular to the second direction. While the soft-pack battery cell is limited on both sides of the first direction by the first plate and the third plate, the soft-pack battery cell can be limited at one end of the first direction by the second plate.

[0019] Exemplarily, the second plate can constrain and limit the soft-pack battery cells in the height direction of the soft-pack battery cells to reduce the vibration of the battery pack relative to the box in the height direction of the battery device, thereby improving the stability and reliability of the battery device.

[0020] According to some embodiments of the present application, the first plate, the second plate and the third plate respectively form two openings on both sides of the third direction, each opening is provided with a busbar for connecting multiple soft-pack battery cells, and each busbar covers the corresponding opening.

[0021] In the above technical solution, the first plate and the third plate are arranged opposite to each other in the first direction, the second plate is located at one end of the first plate and the third plate on the same side of the second direction, and the first plate, the second plate and the third plate respectively define two openings on both sides in the third direction, and the two busbars are respectively arranged on the two openings, so that the space defined by the covering shell for accommodating the soft-pack battery cell can be isolated from the outside world, and then by setting the structural strength and thickness of the covering plate, the insulation effect of thermal runaway can be improved, and the spread speed of thermal runaway can be effectively reduced.

[0022] According to some embodiments of the present application, the battery device further includes: a box body, and the end surfaces of the first plate and the third plate on one side away from the second plate are connected to the box body through an adhesive layer.

[0023] According to some embodiments of the present application, the box body has a bottom plate, and the bottom plate is connected to the first plate and the third plate through an adhesive layer.

[0024] According to some embodiments of the present application, the bottom plate is configured as a cold plate, and / or a cold plate is provided on a side of the bottom plate facing the plurality of soft-pack battery cells, and the glue layer is located between the cold plate and the plurality of soft-pack battery cells.

[0025] In the above technical solution, the bottom plate and the bottom surface of the soft-pack battery cell, and the end surfaces of the second plate and the third plate facing the bottom plate are all connected by an adhesive layer to improve the fixing stability and reliability of the battery pack.

[0026] 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 first plate, and / or between the soft-pack battery cells and the third plate.

[0027] In the above technical solution, when the structural adhesive is used to connect and fix the soft-pack battery cell and the cold plate, at least part of the adhesive layer overflows between adjacent soft-pack battery cells, and / or between the soft-pack battery cell and the first plate, and / or between the soft-pack battery cell and the third plate, and forms an overflowing adhesive portion. By setting the overflowing adhesive portion, not only the area between the adhesive layer and the soft-pack battery cell, and between the adhesive layer and the first plate and the second plate can be increased to improve the fixation stability and reliability of the battery pack on the box, but also the gap between adjacent soft-pack battery cells and between the soft-pack battery cell and the second plate can be filled by the overflowing adhesive portion to achieve the limitation of the soft-pack battery cell and the covering shell, reduce the movement of the battery pack in the box, and reduce the movement of the soft-pack battery cell in the covering shell.

[0028] According to some embodiments of the present application, the flexible shell has a side surface opposite to the large surface of the electrode assembly and a circumferential surface avoiding the large surface, the side surface and / or the circumferential surface are provided with a weak portion, and the covering shell has a pressure relief portion at least partially opposite to the weak portion.

[0029] In the above technical scheme, on the one hand, the gas and fire flow generated after the 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 connection path between the weak part and the pressure relief part is shorter, which can achieve rapid discharge. At the same time, the gas and fire flow stays in the coating 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 the battery pack and the battery device.

[0030] According to some embodiments of the present application, a pressure relief portion is formed on the second plate.

[0031] According to some embodiments of the present application, the second plate is spaced apart from a side of the circumferential surface having the pressure relief portion to define an exhaust passage.

[0032] In the above technical solution, the high-temperature gas and fire flow generated after the weak part ruptures can be first released to the exhaust channel, and after preliminary buffering through the exhaust channel, it can be discharged through the pressure relief part. The pressure of the high-temperature gas and fire flow after flowing out of the pressure relief part can be reduced to reduce the impact and damage after thermal runaway of the soft-pack battery cell.

[0033] According to some embodiments of the present application, the second plate is configured as a straight plate or a curved plate.

[0034] According to some embodiments of the present application, there are multiple pressure relief parts, and the multiple pressure relief parts are arranged at intervals in the length direction and / or width direction of the second plate.

[0035] In the above technical solution, the multiple weak parts on each soft-pack battery cell can have a corresponding pressure relief part, so that the high-temperature gas and fire flow buffered by the exhaust channel can be directly discharged through the corresponding pressure relief part, 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, so as to reduce the spread speed of thermal runaway between adjacent soft-pack battery cells in the battery pack and improve the reliability of the battery pack.

[0036] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells in a single coating shell is less than 0.9 kWh, and the energy density of the multiple soft-pack battery cells in a single coating shell satisfies: L≤450Wh / L.

[0037] In the above technical solution, in the embodiment where the total power in a single coating shell is less than 0.9KWh, the energy density of multiple soft-pack battery cells in a single coating shell should be less than or equal to 450Wh / L, which can improve reliability, reduce the thermal runaway propagation rate between adjacent coating shells, and make the number of soft-pack battery cells in the coating shell more reasonable to take into account space occupancy.

[0038] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells in a single coating shell is less than 0.72 kWh, and the energy density of the multiple soft-pack battery cells in the single coating shell satisfies: 450Wh / L<L≤600 Wh / L.

[0039] In the above technical solution, in the embodiment where the total power in a single coating shell is less than 0.72KWh, the energy density of the multiple soft-pack battery cells in a single coating shell should be greater than 450Wh / L and less than or equal to 600Wh / L, which can improve reliability, reduce the thermal runaway propagation rate between adjacent coating shells, and make the number of soft-pack battery cells in the coating shell more reasonable to take into account space occupancy.

[0040] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells in a single coating shell is less than 0.6 kWh, and the energy density of the multiple soft-pack battery cells in the single coating shell satisfies: 600Wh / L<L≤700Wh / L.

[0041] In the above technical solution, in an embodiment where the total power in a single coating shell is less than 0.6 KWh, the energy density of the multiple soft-pack battery cells in a single coating shell should be greater than 600Wh / L and less than or equal to 700Wh / L, which can improve reliability, reduce the thermal runaway propagation speed between adjacent coating shells, and make the number of soft-pack battery cells 10 in the coating shell more reasonable to take into account space occupancy.

[0042] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells in a single coating shell is less than 0.48 kWh, and the energy density of the multiple soft-pack battery cells in a single coating shell satisfies L>700Wh / L.

[0043] In the above technical solution, in an embodiment where the total power in a single coating shell is less than 0.48 KWh, the energy density of the multiple soft-pack battery cells 10 in a single coating shell should be greater than 700 Wh / L, which can improve reliability, reduce the thermal runaway propagation speed between adjacent coating shells, and make the number of soft-pack battery cells in the coating shell more reasonable to take into account space occupancy.

[0044] 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.

[0045] In the above technical scheme, in the embodiment where the present application is 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 where the present application is 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 improved. In the embodiment where the present application is constructed as a solid-state soft-pack battery cell, not only the energy density can be improved, but also the reliability can be improved.

[0046] In a second aspect, the present application provides an electrical device, including: the battery device in the above embodiment.

[0047] According to some embodiments of the present application, the electrical device is a vehicle.

[0048] 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.

[0049] 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 body participates in defining the vehicle body floor.

[0050] 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.

[0051] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0053] Figure 1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0054] Figure 2 is an exploded schematic diagram of a battery device according to an embodiment of the present application;

[0055] Figure 3 is a schematic diagram of a battery pack according to an embodiment of the present application;

[0056] Figure 4 is a schematic diagram of the cooperation between the battery pack and the box according to an embodiment of the present application;

[0057] Figure 5 is a schematic diagram of the coordination of the busbar, the battery cell and the covering shell according to an embodiment of the present application;

[0058] Figure 6 Schematic diagram of a soft-pack battery cell according to an embodiment of the present application.

[0059] Reference numerals:

[0060] The battery device 100,

[0061] Soft-pack battery cell 10, flexible shell 11, side surface 111, circumferential surface 112, weak part 113, electrode assembly 12,

[0062] The covering shell 20, the first plate 21, the second plate 22, the pressure relief portion 221, the third plate 23,

[0063] Busbar 30,

[0064] Box body 40, bottom plate 41, glue layer 42, glue layer body 421, glue overflow part 422,

[0065] Electrical equipment 200, motor 300, controller 400,

[0066] Exhaust channel a,

[0067] The first direction is X, the second direction is Y, and the third direction is Z. DETAILED DESCRIPTION

[0068] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0070] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0071] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0072] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0073] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0074] 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 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0075] 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 directly in contact with each other, or may include that the first and second features are not in direct contact but are in contact with each other via another feature therebetween.

[0076] In the description of the present invention, a first feature “above”, “over” 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.

[0077] The term “plurality” used in this application refers to two or more (including two).

[0078] The battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged.

[0079] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0080] 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 a plurality of battery cells, which are connected in series, in parallel or in hybrid connection through a busbar.

[0081] In some embodiments, a battery pack is generally formed by arranging a plurality of battery cells.

[0082] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery packs, wherein the battery packs are accommodated in the case.

[0083] As an example, the battery pack may be a battery module, and the battery pack may be accommodated in the box by fixing the battery module in the box.

[0084] As an example, the box may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery pack. The closed space here means covered or closed, which may be sealed or unsealed. The first box may be a top cover or a bottom plate.

[0085] As an example, the box body may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery pack.

[0086] 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.

[0087] The technical solutions described in the embodiments of the present application are applicable to battery devices and electrical equipment using the battery devices.

[0088] Electrical equipment may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may be fuel vehicles, gas vehicles, or new energy vehicles, and new energy vehicles may 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.

[0089] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0090] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application. A battery device 100 is provided inside the vehicle, and the battery device 100 can be provided at the bottom, head, or tail of the vehicle. The battery device 100 can be used to power the vehicle, for example, the battery device 100 can be used as an operating power source for the vehicle.

[0091] 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 of starting, navigating and driving the vehicle.

[0092] In some embodiments of the present application, the battery device 100 can not only be used as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0093] Please refer to Figure 2 , Figure 2 The exploded view of the battery device 100 provided in some embodiments of the present application. The battery device 100 includes a box body 40, and the box body 40 is used to accommodate a battery cell.

[0094] Among them, the box body 40 is a component for accommodating battery cells. The box body 40 provides a placement space for the battery pack, and the box body 40 can adopt a variety of structures. In some embodiments, the box body 40 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 in various shapes, such as a cuboid, 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 40 with a placement space. The tray can also be a hollow structure with one side open, and the cover plate is a plate-like structure. The cover plate covers the open side of the tray, thereby forming a box body 40 with a placement space.

[0095] As an example, the battery cell may be a soft pack battery cell 10 .

[0096] In the battery device 100, there can be one or more battery cells. Multiple battery cells are loaded into a battery pack through the covering shell 20, and one or more battery packs are loaded into the box 40. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells are connected in series and in parallel. Multiple battery cells can be connected in series, in parallel, or in mixed connection to form a battery pack, and multiple battery packs can be connected in series, in parallel, or in mixed connection to form a whole and accommodated in the box 40.

[0097] Combination Figure 5 and Figure 6 The battery cell is the smallest energy unit of the battery device 100 , and the battery cell includes a flexible shell 11 and an electrode assembly 12 disposed in the flexible shell 11 .

[0098] The internal environment formed by the flexible shell 11 can be used to accommodate the electrode assembly 12, electrolyte and other components. An opening can be formed on one side of the flexible shell 11 for injecting electrolyte and the electrode assembly 12 into the shell.

[0099] like Figure 2 , Figure 3 , Figure 5 and Figure 6As shown, the tabs of the electrode assembly 12 are passed through the flexible housing 11, and the tabs are electrically connected to the busbar 30. The electrode assembly 12 is a component in the battery cell where electrochemical reactions occur. The flexible housing 11 may contain one or more electrode assemblies 12. The electrode assembly 12 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 12, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute the tabs. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or at both ends of the main body respectively. During the charge and discharge process of the battery device 100, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the busbar 30 to form a current loop.

[0100] The positive electrode sheet may include a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.

[0101] 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 any one or both of the two opposite surfaces of the positive electrode current collector.

[0102] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, silver surface treated aluminum or stainless steel, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0103] As an example, when the soft-pack battery cell 10 of the 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 to improve the energy density of the soft-pack battery cell 10. However, the present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode film layers can also be used. These positive electrode active materials can be used alone or in combination of two or more.

[0104] 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.

[0105] Layered transition metal oxides include Li a Ni b Co c M d O e A f At least one of the compounds and modified compounds thereof. 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.

[0106] Examples of layered transition metal oxides may 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.

[0107] When the soft-pack battery cell 10 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.

[0108] As an example, the positive electrode 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 / 3 O2, NaFePO4, NaMnPO4, NaCoPO4, Prussian blue materials, general formula X p M' q (PO4) r O x Y 3-x In the general formula X p M' q (PO4) r O x Y 3-x , 0<p≤4, 0<q≤2, 1≤r≤3, 0≤x≤2, X includes at least one of H+, Li+, Na+, K+ and NH4+, M' is a transition metal cation, optionally at least one of V, Ti, Mn, Fe, Co, Ni, Cu and Zn, and Y is a halogen anion, optionally at least one of F, Cl and Br.

[0109] In the embodiments 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.

[0110] The soft-pack battery cell 10 is accompanied by the deintercalation and consumption of active ions such as Li during the charge and discharge process. The molar content of Li is different when the soft-pack battery cell 10 is discharged to different states. In the examples of the positive electrode active materials in the present application, the molar content of Li is the initial state of the material, that is, the state before feeding. The positive electrode active material is used in the battery system. After the charge and discharge cycle, the molar content of Li may change.

[0111] In the examples of the present application regarding the positive electrode active materials, the molar content of oxygen O is only a theoretical value. The release of oxygen from the lattice will cause the molar content of oxygen O to change. In reality, the molar content of oxygen O will fluctuate.

[0112] In the embodiments of the present application, the content of the elements in the positive electrode active material is a well-known meaning in the art, and can be detected by equipment and methods well-known in the art, for example, with reference to EPA 6010D-2014, tested by inductively coupled plasma atomic emission spectrometry, and measured by plasma atomic emission (ICP-OES, instrument model: Thermo ICAP7400). First, weigh 0.4 g of the positive electrode active material and add 10 ml (50% concentration) of aqua regia thereto. Then place it on a plate at 180 ° C for 30 minutes. After digestion on the plate, dilute to a volume of 100 mL, and use the standard curve method for quantitative testing.

[0113] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, or a carbon foam. When the foamed metal is used as the positive electrode, the positive electrode film layer may not be provided on the surface of the foamed metal, but of course, a positive electrode film layer may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0114] In some embodiments, the positive electrode film layer may further optionally include a positive electrode conductive agent. The present application embodiment has no particular restrictions on the type of the positive electrode conductive agent. As an example, the positive electrode conductive agent includes 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 ≤5wt%.

[0115] In some embodiments, the positive electrode film layer may also optionally include a positive electrode binder. The embodiment of the present application has no particular restrictions on the type of positive electrode binder. As an example, the positive electrode binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylic resin. In some embodiments, the mass percentage of the positive electrode binder in the positive electrode film layer is ≤5wt%.

[0116] The positive electrode film layer is usually formed by coating the positive electrode slurry on the positive electrode current collector, drying and cold pressing. The positive electrode slurry is usually formed by dispersing the positive electrode active material, optional conductive agent, optional binder and any other components in a solvent and stirring them evenly. The solvent can be N-methylpyrrolidone (NMP), but is not limited thereto.

[0117] In some embodiments, the negative electrode may be a negative electrode plate, 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.

[0118] 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 any one or both of the two opposite surfaces of the negative electrode current collector.

[0119] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0120] As an example, the negative electrode active material may adopt the negative electrode active material for the soft-pack battery cell 10 known in the art. As an example, the negative electrode active material may include at least one of the following materials: carbon material (for example, the carbon material includes at least one of artificial graphite, natural graphite, soft carbon, and hard carbon), silicon-based material, tin-based material, lithium titanate, etc. The silicon-based material may include at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may include at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional 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.

[0121] In some embodiments, the negative electrode active material includes silicon, which may be present in the form of a silicon-based material, such as a silicon-based material that may include at least one of elemental silicon, silicon-oxygen compounds, silicon-carbon compounds, silicon-nitrogen compounds, and silicon alloys. The introduction of silicon can improve the energy density of the soft-pack battery cell 10.

[0122] In some embodiments, the mass content of silicon in the negative electrode film layer is 1wt% to 32wt%, optionally 2wt% to 19wt%, and further optionally 6wt% to 13wt%. In the soft-pack battery cell 10 system, when the mass content of silicon is within the above range, the energy density of the soft-pack battery cell 10 can be improved.

[0123] 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 immersed in a solvent such as water, 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, and with reference to GB / T30902-2014 standard to obtain the silicon content.

[0124] In some embodiments, the negative electrode film layer may further optionally include a negative electrode conductive agent. The embodiment of the present application has no particular restrictions on the type of the negative electrode conductive agent. As an 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 ≤5wt%.

[0125] In some embodiments, the negative electrode film layer may also optionally include a negative electrode binder. The embodiment of the present application has no particular restrictions on the type of negative electrode binder. As an example, the negative electrode binder may include at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based acrylic resin (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA) and carboxymethyl chitosan (CMCS). In some embodiments, the mass percentage of the negative electrode binder in the negative electrode film layer is ≤5%.

[0126] In some embodiments, the negative electrode film layer may further include other additives. As an example, the other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC-Na), PTC thermistor materials, etc. In some embodiments, the mass percentage of the other additives in the negative electrode film layer is ≤ 2wt%.

[0127] 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.

[0128] 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.

[0129] The embodiments of the present application have no particular restrictions on the type of isolation membrane, and any known porous structure isolation membrane with good chemical stability and mechanical stability can be selected.

[0130] In some embodiments, the material of the isolation membrane may include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane may be a single-layer film or a multi-layer composite film, without particular limitation. When the isolation membrane is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0131] In some embodiments, the isolation membrane 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.

[0132] The porous base membrane may include one or more of polyethylene and polypropylene.

[0133] The inorganic particles have good heat resistance and can improve the heat resistance of the separator as a whole. The inorganic particles will not undergo oxidation and reduction reactions with metal dendrites within the operating voltage range of the sodium ion battery. In other words, the inorganic particles are configured not to undergo oxidation and reduction reactions with alkali metals and / or alkaline earth metals at the nominal voltage of the sodium ion battery.

[0134] 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.

[0135] 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.

[0136] In some embodiments, the soft pack battery cell 10 further includes an electrolyte.

[0137] During the charge and discharge process of the battery cell, active ions are embedded and released back and forth between the positive electrode and the negative electrode, and the electrolyte plays a role in conducting active ions between the positive electrode and the negative electrode. The present application embodiment has no particular limitation on the type of electrolyte, which can be selected according to actual needs.

[0138] The electrolyte includes electrolyte salt and solvent. The types of electrolyte salt and solvent are not specifically limited and can be selected according to actual needs.

[0139] In some embodiments, the electrolyte may also optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery 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.

[0140] 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.

[0141] In the related art, the covering shell 20 is arranged outside a plurality of soft-pack battery cells 10 and is used to support the soft-pack battery cells 10. When the soft-pack battery cells 10 experience thermal runaway, it is difficult for the covering shell 20 to effectively dissipate heat, and the high-temperature gas and fire flow (high-temperature gas entraining solid particles or liquid) generated during thermal runaway will impact the covering shell 20, resulting in the covering shell 20 being unable to effectively block heat diffusion, posing a safety hazard.

[0142] Based on this, the present application proposes a battery device 100, in which the covering shell 20 has higher structural strength, more reasonable wall thickness, better heat dissipation effect, and better impact resistance, which can effectively block heat diffusion to reduce safety hazards and improve the reliability of the battery device 100.

[0143] Reference below Figure 1-Figure 6 A battery device 100 and a power-consuming device 200 according to an embodiment of the present invention are described.

[0144] like Figure 2 As shown, the present application provides a battery device 100 , which may include: a box body 40 and at least one battery pack disposed in the box body 40 , and the battery pack may include a plurality of soft-pack battery cells 10 and a covering shell 20 .

[0145] Among them, Figure 3 and Figure 4 As shown, a plurality of soft-pack battery cells 10 are stacked in sequence and electrically connected; a covering shell 20 covers the plurality of soft-pack battery cells 10 , and the covering shell 20 is configured to constrain the plurality of soft-pack battery cells 10 from at least three directions.

[0146] That is to say, the covering shell 20 includes at least three plates, one of which constrains the multiple soft-pack battery cells 10 in a first direction, and the other two plates are arranged relatively to each other and are used to constrain the multiple soft-pack battery cells 10 in a second direction having an angle with the first direction, such as: one plate constrains the multiple soft-pack battery cells 10 above or below the height direction, and the other two plates constrain the multiple soft-pack battery cells 10 on the left and right sides in the width direction, so as to realize the constraint of the multiple soft-pack battery cells 10 from at least three directions, improve the constraining stability and reliability of the covering shell 20 on the soft-pack battery cells 10, reduce the movement of the soft-pack battery cells 10, and improve the reliability and stability of the battery pack.

[0147] Furthermore, the strength of the coating shell 20 is made higher than the strength of the flexible shell 11 of the soft-pack battery cell 10, that is, the soft-pack battery cell 10 has a flexible shell 11, an electrode assembly 12 is arranged in the flexible shell 11, and a weak portion 113 can be arranged on the flexible shell 11, so that when the soft-pack battery cell 10 has thermal runaway, pressure relief protection can be achieved, and the strength of the coating shell 20 is higher than that of the flexible shell 11. When the soft-pack battery cell 10 has thermal runaway, while the weak portion 113 is implemented for pressure relief protection, it can be ensured that the coating shell 20 will not be structurally damaged (such as rupture, opening, etc.) under the impact of the high-pressure gas and fire flow, so that the high-pressure gas and fire flow can be blocked inside the coating shell 20 by the coating shell 20.

[0148] It should be noted that the thickness of the plate body of the covering shell 20 constraining the plurality of soft-pack battery cells 10 is less than or equal to 5.2 mm and greater than or equal to 0.2 mm.

[0149] Exemplarily, the thickness of the plate of the covering shell 20 used to constrain the plurality of soft-pack battery cells 10 is 0.2 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 5.2 mm, etc.

[0150] That is to say, the thickness of the plate body of the covering shell 20 is between 0.2 mm and 5.2 mm. On the one hand, it can avoid the thickness of the plate body being too thin and improve the impact resistance of the covering shell 20 so that the covering shell 20 can better cover and protect the soft-pack battery cell 10. On the other hand, it can avoid the thickness of the plate body being too thick to take into account both material cost and space occupancy, that is, to take into account both production cost and energy density.

[0151] At the same time, making the wall thickness of the covering shell 20 more reasonable can also improve the heat dissipation effect of the covering shell 20 .

[0152] According to the battery device 100 of the embodiment of the present application, by making the strength of the covering shell 20 higher than the strength of the flexible shell 11 and making the thickness of the covering shell 20 more reasonable, on the one hand, the structural strength of the covering shell 20 can be improved, and the probability of structural damage to the covering shell 20 after being impacted by the high-pressure gas fire flow can be reduced, so that the heat diffusion of the soft-pack battery cell 10 is concentrated inside the covering shell 20, and the probability of heat diffusion outside the covering shell 20 is reduced, so as to improve the reliability of the battery device 100. On the other hand, the energy density of the battery device 100 can be taken into account and the production cost of the battery device 100 can be reduced.

[0153] According to some embodiments of the present application, the thickness of the plate of the covering shell 20 constraining the plurality of soft-pack battery cells 10 is less than or equal to 3 mm and greater than or equal to 0.5 mm.

[0154] Specifically, the coating shell 20 constrains the plate thickness of multiple soft-pack battery cells 10 to be 0.5mm~3mm, such as: the plate thickness is 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, so that the thickness of the coating shell 20 does not exceed 3mm, taking into account the space occupied by the coating shell 20 and improving the energy density of the battery device 100, and is not less than 0.5mm, to ensure that the structural strength of the coating shell 20 can meet the use requirements. Under the impact of high-pressure gas and fire flow, the probability of structural damage to the coating shell 20 is smaller, and the heat dissipation effect of the plate with a more reasonable thickness size is better, which can improve heat concentration to reduce the probability of the coating shell 20 melting due to heat, so as to improve the insulation effect of the coating shell 20 against thermal runaway, so as to make the battery device 100 more reliable.

[0155] According to some embodiments of the present application, the thickness of the plate of the covering shell 20 constraining the plurality of soft-pack battery cells 10 is less than or equal to 1 mm and greater than or equal to 0.6 mm.

[0156] Furthermore, the coating shell 20 constrains the plate thickness of multiple soft-pack battery cells 10 to be 0.6mm~1mm, such as: the plate thickness is 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm. On the one hand, the plate thickness is greater than 0.6mm to ensure the structural strength while taking into account the heat dissipation effect of the plate and improving the heat concentration of the plate to improve the insulation effect of thermal runaway and effectively delay the spread of thermal runaway to the outside. On the other hand, the plate thickness is less than 1mm, which can reduce the material cost of the coating shell 20 to reduce the production cost, and make the space occupied by the coating shell 20 more reasonable, taking into account the energy density of the battery device 100.

[0157] According to some embodiments of the present application, the covering shell 20 is an aluminum shell, and the thickness of the plate body of the multiple soft-pack battery cells 10 constrained by the covering shell 20 is less than or equal to 1 mm and greater than or equal to 0.4 mm; or the covering shell 20 is a stainless steel shell, and the thickness of the plate body of the multiple soft-pack battery cells 10 constrained by the covering shell 20 is less than or equal to 1 mm and greater than or equal to 0.2 mm.

[0158] Specifically, in some embodiments, the covering shell 20 is an aluminum shell, and the plate thickness of the covering shell 20 is in the range of 0.4 mm to 1 mm. In other embodiments, the covering shell 20 is a stainless steel shell, and the plate thickness of the covering shell 20 is in the range of 0.2 mm to 1 mm.

[0159] In this way, based on the different materials of the covering shell 20, when the covering shell 20 is constructed as an aluminum material, the minimum thickness of the plate body is made larger to reduce the probability of structural damage after heat concentration in the covering shell 20, thereby improving reliability. When the covering shell 20 is constructed as a stainless steel material, the minimum thickness of the plate body is made smaller, which can further improve the space occupied by the covering shell 20.

[0160] like Figure 3 and Figure 4 As shown, according to some embodiments of the present application, the covering shell 20 includes a first plate 21, a second plate 22 and a third plate 23 that are bent and connected in sequence, and the first plate 21 and the third plate 23 form an opening on the side away from the second plate 22, and the covering shell 20 is connected to the box body 40 of the battery device 100 through the opening position; the first plate 21, the second plate 22 and the third plate 23 respectively constrain multiple soft-pack battery cells 10 along three directions.

[0161] Specifically, the first plate 21 and the third plate 23 are arranged opposite to each other, and the second plate 22 is located at one end on the same side of the first plate 21 and the third plate 23, so that the other end on the same side of the first plate 21 and the third plate 23 defines an opening, and the opening position is used to connect with the box body 40, that is, the end surface of the first plate 21 and the third plate 23 on one side away from the second plate 22 is connected to the box body 40, so that the soft-pack battery cell 10 is constrained by the first plate 21, the second plate 22 and the third plate 23 on two opposite surfaces and one adjacent surface of the soft-pack battery cell 10 respectively. While improving the constraining effect on the battery cell, the connection between the covering shell 20 and the box body 40, and the connection between the soft-pack battery cell 10 and the box body 40 can be located on the same side, which can also reduce the difficulty of assembly and improve the assembly efficiency.

[0162] It can be understood that the plate thickness of the first plate 21 and the third plate 23 meets the above-mentioned size range, which can take into account the space occupied by the battery pack in the direction of the first plate 21 and the third plate 23, and the plate thickness of the second plate 22 meets the above-mentioned size range, which can take into account the space occupied by the battery pack in the direction of the second plate 22.

[0163] like Figure 4 As shown, according to some embodiments of the present application, the first plate 21 and the third plate 23 constrain the plurality of soft-pack battery cells 10 in opposite directions.

[0164] Specifically, the first plate 21 and the third plate 23 are arranged opposite to each other, and by constraining the soft-pack battery cell 10 in opposite directions by the oppositely arranged first plate 21 and the third plate 23, the movement of the soft-pack battery cell 10 can be reduced, and the fixing stability and reliability of the battery pack in the box 40 can be improved.

[0165] Exemplarily, the first plate 21 and the third plate 23 can constrain and limit the soft-pack battery cell 10 in the width direction of the soft-pack battery cell 10, and the width direction of the soft-pack battery cell 10 can correspond to the width direction or length direction of the battery device 100, so that the soft-pack battery cell 10 can be limited in the width or length direction of the battery device 100, so as to reduce the movement of the battery pack relative to the box body 40 in the width direction or length direction of the battery device 100, and improve the stability and reliability of the battery device 100.

[0166] Combination Figure 4 and Figure 5 As shown, according to some embodiments of the present application, the direction in which the second plate 22 constrains the plurality of soft-pack battery cells 10 is perpendicular to the direction in which the first plate 21 or the third plate 23 constrains the plurality of soft-pack battery cells 10 .

[0167] Among them, the second plate 22 is respectively connected to the first plate 21 and the third plate 23 on both sides of the first direction to limit an opening in the second direction, and the surface of the soft-pack battery cell 10 on one side of the opening can be connected to the box body 40, and the first direction is perpendicular to the second direction. While the soft-pack battery cell 10 is limited on both sides of the first direction by the first plate 21 and the third plate 23, the soft-pack battery cell 10 can be limited at one end of the first direction by the second plate 22.

[0168] Exemplarily, the second plate 22 can constrain and limit the soft-pack battery cell 10 in the height direction of the soft-pack battery cell 10 to reduce the jumping of the battery pack relative to the box 40 in the height direction of the battery device 100 and improve the stability and reliability of the battery device 100.

[0169] like Figure 5 As shown, according to some embodiments of the present application, the first plate 21, the second plate 22 and the third plate 23 respectively form two openings on both sides of the third direction, and each opening is provided with a busbar 30 for connecting multiple soft-pack battery cells 10, and each busbar 30 covers the corresponding opening.

[0170] Specifically, the first plate 21 and the third plate 23 are arranged opposite to each other in the first direction, the second plate 22 is located at the end of the first plate 21 and the third plate 23 on the same side in the second direction, and the first plate 21, the second plate 22 and the third plate 23 define two openings on both sides in the third direction, respectively, and the two busbars 30 are respectively arranged on the two openings, so that the space defined by the covering shell 20 for accommodating the soft-pack battery cell 10 can be isolated from the outside world, and then by setting the structural strength and thickness of the covering plate, the insulation effect of thermal runaway can be improved, and the spread speed of thermal runaway can be effectively reduced.

[0171] It should be noted that the first direction is the width direction of the soft-pack battery cell 10 , the second direction is the height direction of the soft-pack battery cell 10 , and the third direction is the length direction of the soft-pack battery cell 10 .

[0172] like Figure 2 As shown, the battery device 100 includes a box body 40 and a battery pack, there is at least one battery pack, and the battery pack includes: at least one soft-pack battery cell 10 in the above embodiment and a covering shell 20, at least one side surface of the covering shell 20 has a pressure relief portion 221.

[0173] Among them, a containing space is formed in the box body 40, and one or more battery packs are arranged in the containing space. One or more soft-pack battery cells 10 are arranged inside the covering shell 20 of each battery pack, and the soft-pack battery cells 10 are constructed as the soft-pack battery cells 10 using the above-mentioned flexible shell 11.

[0174] like Figure 4 and Figure 6 As shown, according to some embodiments of the present application, the flexible shell 11 has a side surface 111 opposite to the large surface of the electrode assembly 12 and a circumferential surface 112 avoiding the large surface, the side surface 111 and / or the circumferential surface 112 are provided with a weak portion 113, and the covering shell 20 has a pressure relief portion 221 at least partially opposite to the weak portion 113.

[0175] Among them, the covering shell 20 is at least used to cover at least one of the multiple circumferential surfaces 112 and two side surfaces 111 of the soft-pack battery cell 10, and a weak portion 113 is provided on at least one circumferential surface 112 of the soft-pack battery cell 10, and a pressure relief portion 221 is formed on at least one side of the covering shell 20, such as the pressure relief portion 221 is opposite to the weak portion 113, or the pressure relief portion 221 is located on the first surface of the covering shell 20, and the weak portion 113 is opposite to the second surface of the covering shell 20, and the first surface is adjacent to the second surface.

[0176] In this way, by providing a pressure relief portion 221 that cooperates with the weak portion 113 on the covering shell 20, when the soft-pack battery cell 10 has thermal runaway, the high-temperature gas and fire flow discharged through the weak portion 113 can be further released outward through the pressure relief portion 221, so as to achieve directional discharge of the high-temperature gas and fire flow through the cooperation between the weak portion 113 and the pressure relief portion 221, so as to improve the reliability of the battery device 100.

[0177] like Figure 6 As shown, according to some embodiments of the present application, the second plate 22 is opposite to the side surface 111 , and the projection contour area of ​​the second plate 22 toward the side surface 111 of the flexible housing 11 is less than or equal to the area of ​​the side surface 111 .

[0178] Specifically, the circumferential surface 112 is defined to include a first surface and a second surface opposite thereto, the first surface is opposite to the first plate 21, the second surface is arranged away from the first plate 21, and the second surface is used to connect to the box body 40, the two sides of the first surface and the second surface are respectively the two side surfaces 111 of the soft-pack battery cell 10, the two ends of the first surface and the second surface are respectively the other two circumferential surfaces 112 of the soft-pack battery cell 10, and the second plate 22 is opposite to the side surface 111, so as to limit the soft-pack battery cell 10 in the direction where the second plate 22 is located, and the area size of the surface of the second plate 22 opposite to the side surface 111 can be less than or equal to the area size of the side surface 111.

[0179] That is to say, in some embodiments, the size of the second plate 22 is consistent with the size of the side 111, and in other embodiments, the size of the second plate 22 is smaller than the size of the side 111. On the one hand, it can avoid the second plate 22 being too large, resulting in the second surface being unable to connect to the box 40, and can improve the fixation stability and reliability of the battery pack in the box 40. On the other hand, the material used for the second plate 22 can be less, and the material cost of the battery pack and the battery device 100 can also be reduced.

[0180] According to some embodiments of the present application, the battery device 100 further includes: a box body 40 , and the end surfaces of the first plate 21 and the third plate 23 on one side away from the second plate 22 are connected to the box body 40 via an adhesive layer 42 .

[0181] Specifically, the box body 40 has a bottom plate 41, which is connected to the bottom surface (i.e., the second surface) of the soft-pack battery cell 10, the second plate 22, and the end surface of the third plate 23 facing the bottom plate 41 by an adhesive layer 42 to improve the fixing stability and reliability of the battery pack.

[0182] like Figure 5 As shown, according to some embodiments of the present application, the bottom plate 41 includes a cold plate, and the glue layer 42 is located between the cold plate and the plurality of soft-pack battery cells 10 .

[0183] In some embodiments, the bottom plate 41 of the box body 40 is formed as a cold plate, and the cold plate is connected to the soft-pack battery cell 10 through the glue layer 42. In other embodiments, a cold plate is arranged between the bottom plate 41 and the soft-pack battery cell 10, and the cold plate is connected to the soft-pack battery cell 10 through the glue layer 42.

[0184] That is to say, the adhesive layer 42 is constructed as structural adhesive, and the bottom plate 41 provided with a cold plate is connected to the soft-pack battery cell 10. On the premise of achieving stable and reliable fixation of the battery pack in the box body 40, 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 reduce the probability of thermal runaway of the battery pack, thereby improving the reliability of the battery pack and even the battery device 100.

[0185] like Figure 5 As shown, according to some embodiments of the present application, the glue layer 42 includes: a glue layer body 421 and a glue overflow portion 422, the glue overflow portion 422 is located on the side of the glue layer body 421 facing the multiple soft-pack battery cells 10, and is located between adjacent soft-pack battery cells 10, and / or between the soft-pack battery cells 10 and the first plate 21, and / or between the soft-pack battery cells 10 and the third plate 23.

[0186] That is to say, when the structural adhesive is used to connect and fix the soft-pack battery cell 10 to the cold plate, at least part of the glue layer 42 overflows between adjacent soft-pack battery cells 10, and / or between the soft-pack battery cell 10 and the first plate 21, and / or between the soft-pack battery cell 10 and the third plate 23, and forms an overflow glue portion 422. By setting the overflow glue portion 422, not only the area between the glue layer 42 and the soft-pack battery cell 10, the glue layer 42 and the first plate 21, and the second plate 22 can be increased to improve the fixation stability and reliability of the battery pack on the box 40, but also the gap between adjacent soft-pack battery cells 10 and between the soft-pack battery cell 10 and the second plate 22 can be filled by the overflow glue portion 422 to achieve the limitation of the soft-pack battery cell 10 and the covering shell 20, reduce the movement of the battery pack in the box 40, and reduce the movement of the soft-pack battery cell 10 in the covering shell 20.

[0187] The first plate 21 and the third plate 23 are respectively arranged on both sides of the second plate 22. The second plate 22 of the covering shell 20 can be opposite to a circumferential surface 112 of the soft-pack battery cell 10, and the first plate 21 and the third plate 23 can be opposite to the side surfaces 111 of the soft-pack battery cell 10 respectively. The weak portion 113 formed on the circumferential surface 112 can be at least partially opposite to the pressure relief portion 221 formed on the second plate 22 (that is, the pressure relief portion 221 is formed on the second plate 22).

[0188] It should be pointed out that the weak portion 113 and the pressure relief portion 221 are at least partially opposite to each other, which means that the weak portion 113 formed on the circumferential surface 112 is projected toward the first plate 21 , and the projection contour at least partially overlaps with the contour of the pressure relief portion 221 .

[0189] In this way, on the one hand, the gas and fire flow generated after the thermal runaway of the soft-pack battery cell 10 can be discharged in a direction and orderly to reduce damage, especially secondary damage. On the other hand, the communication path between the weak portion 113 and the pressure relief portion 221 is shorter, which can achieve rapid discharge while the gas and fire flow stays in the covering shell 20 for a shorter time, which has less impact on other soft-pack battery cells 10 around the thermal runaway soft-pack battery cell 10, and can further reduce the spread speed of thermal runaway, thereby improving the reliability of the battery pack and the battery device 100.

[0190] like Figure 4 and Figure 5 As shown, according to some embodiments of the present application, the second plate 22 is spaced apart from a side of the circumferential surface 112 having the pressure relief portion 221 to define an exhaust channel a.

[0191] In this way, the high-temperature gas and fire flow generated after the weak part 113 ruptures can be first discharged to the exhaust channel a, and after preliminary buffering through the exhaust channel a, it can be discharged through the pressure relief part 221, which can reduce the pressure of the high-temperature gas and fire flow after flowing out of the pressure relief part 221, so as to reduce the impact and damage of the soft-pack battery cell 10 after thermal runaway.

[0192] According to some embodiments of the present application, the second plate 22 is configured as a straight plate or a curved plate.

[0193] That is, in some embodiments, the second plate 22 is configured as a straight plate, and in other embodiments, the second plate 22 is configured as a curved plate.

[0194] According to some embodiments of the present application, there are multiple pressure relief portions 221 , and the multiple pressure relief portions 221 are arranged at intervals in the length direction and / or width direction of the second plate 22 .

[0195] Thus, the multiple weak parts 113 on each soft-pack battery cell 10 can have a corresponding pressure relief part 221, 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 221, 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 10 in the battery pack and improve the reliability of the battery pack.

[0196] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells 10 in a single coating shell 20 is less than 0.9 kWh, and the energy density of the multiple soft-pack battery cells 10 in a single coating shell 20 satisfies: L≤450 Wh / L.

[0197] In this way, in an embodiment where the total power in a single coating shell 20 is less than 0.9 KWh, the energy density of the multiple soft-pack battery cells 10 in a single coating shell 20 should be less than or equal to 450 Wh / L, which can improve reliability, reduce the thermal runaway propagation speed between adjacent coating shells 20, and make the number of soft-pack battery cells 10 in the coating shell 20 more reasonable to take into account space occupancy.

[0198] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells 10 in a single coating shell 20 is less than 0.72 kWh, and the energy density of the multiple soft-pack battery cells 10 in a single coating shell 20 satisfies: 450 Wh / L<L≤600 Wh / L.

[0199] In this way, in an embodiment where the total power in a single coating shell 20 is less than 0.72 KWh, the energy density of the multiple soft-pack battery cells 10 in a single coating shell 20 should be greater than 450 Wh / L and less than or equal to 600 Wh / L, which can improve reliability, reduce the thermal runaway propagation speed between adjacent coating shells 20, and make the number of soft-pack battery cells 10 in the coating shell 20 more reasonable to take into account space occupancy.

[0200] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells 10 in a single coating shell 20 is less than 0.6 kWh, and the energy density of the multiple soft-pack battery cells 10 in a single coating shell 20 satisfies: 600 Wh / L<L≤700 Wh / L.

[0201] In this way, in an embodiment where the total power in a single coating shell 20 is less than 0.6 KWh, the energy density of the multiple soft-pack battery cells 10 in a single coating shell 20 should be greater than 600 Wh / L and less than or equal to 700 Wh / L, which can improve reliability, reduce the thermal runaway propagation speed between adjacent coating shells 20, and make the number of soft-pack battery cells 10 in the coating shell 20 more reasonable to take into account space occupancy.

[0202] According to some embodiments of the present application, the total power of the multiple soft-pack battery cells 10 in a single coating shell 20 is less than 0.48 kWh, and the energy density of the multiple soft-pack battery cells 10 in the single coating shell 20 satisfies L>700 Wh / L.

[0203] In this way, in an embodiment where the total power in a single coating shell 20 is less than 0.48 KWh, the energy density of the multiple soft-pack battery cells 10 in a single coating shell 20 should be greater than 700 Wh / L, which can improve reliability, reduce the thermal runaway propagation speed between adjacent coating shells 20, and make the number of soft-pack battery cells 10 in the coating shell 20 more reasonable to take into account space occupancy.

[0204] It should be pointed out that the test conditions of the embodiment of the present application are to set two adjacent battery packs in the closed space of a box body simulating a battery device, one of the two battery packs has thermal runaway (e.g., short-circuiting is used to trigger thermal runaway), the other battery pack is a battery pack in a normal state, and the coating shells 20 of the two battery packs are used to constrain the plate thickness of the soft-pack battery cells 10 to be consistent (taking a minimum value of 0.2 mm), the total power of the multiple soft-pack battery cells 10 in the two battery packs is consistent, and based on national standards, a threshold value of the allowable time for the thermal runaway of one battery pack to cause the thermal runaway of another battery pack is set between two adjacent battery packs (e.g., GB The national standard 38031 requires that the battery device 100 does not catch fire within five minutes after the battery cell thermal runaway occurs. Based on this, the allowable time threshold can be set to 5 minutes), and then it is judged whether the battery pack 10 in a normal state is affected by the spread of thermal runaway between adjacent battery packs 10, and whether the time taken for thermal runaway to occur reaches or exceeds the allowable time threshold. Reaching or exceeding the allowable time threshold is defined as no spread, so as to determine the energy density limit value of the soft-pack battery cell in the battery pack under the total power, and further adjust the total power size to determine the corresponding energy density limit value under different total power conditions, and then determine the relationship between the total power of multiple soft-pack battery cells 10 in a single covering shell 20 and the energy density of the soft-pack battery cells 10.

[0205] For example, the length dimension of the soft-pack battery cell 10 is 355 mm, the width dimension is 13.8 mm, and the height dimension is 123 mm. In a specific embodiment in which the thickness of the plate of the cover shell 20 constraining the plurality of soft-pack battery cells 10 is 0.2 mm, the heat diffusion under the same energy density and different internal electric quantities is as follows:

[0206]

[0207] In summary, the present application reasonably sets the energy density of the soft-pack battery cells 10 based on the total power of multiple soft-pack battery cells 10 in each battery pack, such as: when the energy density is less than or equal to 450Wh / L, the total power should be less than 0.9 kWh, when the energy density is in the range of 450 Wh / L<L≤600 Wh / L, the total power should be less than 0.72 kWh, when the energy density is in the range of 600 Wh / L<L≤700 Wh / L, the total power should be less than 0.6 kWh, and when the energy density is greater than 700 Wh / L, the total power should be less than 0.48 kWh.

[0208] Therefore, based on the above table, it can be seen that by reasonably setting the corresponding relationship between the total power and the energy density, the thermal runaway suppression effect when the soft-pack battery cell 10 in the battery pack occurs thermal runaway can be improved, the propagation speed of the thermal runaway can be reduced, and the reliability can be improved.

[0209] As shown in the accompanying drawings, the soft-pack battery cell 10 of the embodiment of the present application is constructed as a soft-pack battery cell 10, the electrode assembly 12 is arranged in the flexible shell 11, and the flexible shell 11 has a weak portion 113 formed on at least the circumferential surface 112. The battery pack includes at least one soft-pack battery cell 10 of the embodiment of the present application, and the pressure relief portion 221 on the first plate 21 of the covering shell 20 is at least partially opposite to the weak portion 113, and the second plate 22 is opposite to the side 111 of the flexible shell 11. The bottom plate 41 of the box body 40 is constructed as a cold plate, or a cold plate is arranged above the bottom plate 41, and the cold plate is connected to the soft-pack battery cell 10 through the glue layer 42, and the overflow glue portion 422 of the glue layer 42 overflows to between adjacent soft-pack battery cells 10, and / or between the soft-pack battery cell 10 and the second plate 22.

[0210] According to some embodiments of the present application, the soft-pack battery cell 10 is any one of a lithium iron phosphate battery cell, a ternary lithium battery cell, and a solid-state battery cell.

[0211] That is, in some embodiments, the soft-pack battery cell 10 is configured as a lithium iron phosphate battery, in some embodiments, the soft-pack battery cell 10 is configured as a ternary lithium battery cell, and in some embodiments, the soft-pack battery cell 10 is configured as a solid-state battery cell.

[0212] 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.

[0213] In the above technical scheme, in the embodiment where the present application is 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 where the present application is 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 improved. In the embodiment where the present application is constructed as a solid-state soft-pack battery cell, not only the energy density can be improved, but also the reliability can be improved.

[0214] According to some embodiments of the present application, when the soft-pack battery cell 10 is a lithium iron phosphate (LiFeO4) battery cell, the positive electrode material of the soft-pack battery cell 10 includes a positive electrode active material, a positive electrode binder, and a positive electrode conductive agent in a ratio of 96:1-3:1-3; when the soft-pack battery cell 10 is a ternary lithium battery cell, and the positive electrode material of the soft-pack battery cell 10 includes a positive electrode active material, a positive electrode binder, and a positive electrode conductive agent in a ratio of 96:2-3:1-2.

[0215] It can be understood that when the soft-pack battery cell 10 is a lithium iron phosphate battery cell, in the positive electrode material of the soft-pack battery cell 10, 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.).

[0216] For example, when the soft-pack battery cell 10 is a lithium iron phosphate battery cell, the positive electrode active material is LFP (which may refer to LiFePO4, i.e., lithium iron phosphate), the binder may be PVDF (polyvinylidene fluoride), and the conductive agent may be conductive carbon black, wherein LFP:PVDF:conductive carbon black may be 96:2:2, that is, the total weight of the positive electrode active material is 100 parts, LFP accounts for 96 parts, PVDF accounts for 2 parts, and conductive carbon black also accounts for 2 parts. The weight unit of the positive electrode active material may be grams.

[0217] When the soft-pack battery cell 10 is a ternary battery cell, in the positive electrode material of the soft-pack battery cell 10, the positive electrode active material accounts for 96 parts of the total weight of the positive electrode material, the binder accounts for 2-3 parts of the total weight of the positive electrode material (for example, including but not limited to 2, 2.2, 2.5, 2.8, 3, etc.), and the conductive agent accounts for 1-2 parts of the total weight of the positive electrode material (for example, including but not limited to 1, 1.2, 1.5, 1.8, 2, etc.). Among them, the ternary battery cell can be but not limited to nickel cobalt manganese lithium oxide system, nickel cobalt aluminum oxide lithium oxide system, etc.

[0218] 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, 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.

[0219] In the above technical solution, when the soft-pack battery cell 10 is a lithium iron phosphate battery cell, a high proportion of positive electrode active material means that more substances capable of electrochemical reactions can be accommodated in a limited electrode assembly, which is beneficial to increasing the capacity and energy density of the battery device 100, so that the lithium iron phosphate battery cell can output a higher amount of electricity in a relatively small volume and weight, meeting the application scenario with certain requirements for energy density. The amount of the binder and the conductive agent used in the above range can reduce the cost of auxiliary materials, thereby reducing the overall cost of the battery device 100. When the soft-pack battery cell 10 is a ternary battery cell, since the structure and surface properties of the ternary material itself are relatively complex, the use of the positive electrode active material, binder, and conductive agent in the above-mentioned dosage ratio is beneficial to ensure 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, and is beneficial to reducing the risk of active material shedding and electrode pulverization during charging and discharging, and extending the cycle life of the battery device 100.

[0220] like Figure 1 As shown, the present application proposes an electric device 200, comprising: the battery device 100 in the above embodiment.

[0221] 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, so that the top plate of the box body 40 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 100 is larger and the energy density is higher.

[0222] It is understandable that the electrical device 200 is constructed as a vehicle, that is, the vehicle adopts the above-mentioned battery device 100. The battery device 100 has a higher energy density and higher reliability, which can improve the driving safety of the vehicle while improving the cruising range of the vehicle.

[0223] Other structures and operations of the soft-pack battery cell 10 , the battery device 100 and the electrical equipment 200 according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0224] In the description of this specification, the description with reference to the terms "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 the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0225] 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 spirit 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, characterized in that: include: A plurality of soft-pack battery cells (10), wherein the plurality of soft-pack battery cells (10) are stacked in sequence and electrically connected; A covering shell (20), the covering shell (20) covering the outside of the plurality of soft-pack battery cells (10), and the covering shell (20) being configured to constrain the plurality of soft-pack battery cells (10) from at least three directions; the strength of the covering shell (20) is higher than the strength of the flexible outer shell (11) of the soft-pack battery cells (10); The thickness of the plate body of the covering shell (20) constraining the plurality of soft-pack battery cells (10) is less than or equal to 5.2 mm and greater than or equal to 0.2 mm.

2. The battery device according to claim 1, characterized in that: The thickness of the plate body of the covering shell (20) constraining the plurality of soft-pack battery cells (10) is less than or equal to 3 mm and greater than or equal to 0.5 mm.

3. The battery device according to claim 1, characterized in that: The thickness of the plate body of the covering shell (20) constraining the plurality of soft-pack battery cells (10) is less than or equal to 1 mm and greater than or equal to 0.6 mm.

4. The battery device according to claim 1, characterized in that: The covering shell (20) is an aluminum shell, and the thickness of the plate body of the covering shell (20) constraining the plurality of soft-pack battery cells (10) is less than or equal to 1 mm and greater than or equal to 0.4 mm; or, The covering shell (20) is a stainless steel shell, and the thickness of the plate body of the covering shell (20) constraining the plurality of soft-pack battery cells (10) is less than or equal to 1 mm and greater than or equal to 0.2 mm.

5. The battery device according to claim 1, characterized in that: The covering shell (20) comprises a first plate (21), a second plate (22) and a third plate (23) which are bent and connected in sequence, and the first plate (21) and the third plate (23) form an opening on a side facing away from the second plate (22); the covering shell (20) is connected to the box body (40) of the battery device through the opening; The first plate (21), the second plate (22), and the third plate (23) respectively constrain the plurality of soft-pack battery cells (10) in three directions.

6. The battery device according to claim 5, characterized in that: The first plate (21) and the third plate (23) constrain the plurality of soft-pack battery cells (10) in opposite directions.

7. The battery device according to claim 6, characterized in that: The direction in which the second plate (22) constrains the plurality of soft-pack battery cells (10) is perpendicular to the direction in which the first plate (21) or the third plate (23) constrains the plurality of soft-pack battery cells (10).

8. The battery device according to claim 5, characterized in that: The first plate (21), the second plate (22) and the third plate (23) respectively form two openings on both sides of the third direction, each of the openings being provided with a busbar (30) for busbaring a plurality of the soft-pack battery cells (10), and each of the busbars (30) covers the corresponding opening.

9. The battery device according to claim 5, characterized in that: The battery device further comprises a box body (40), and end surfaces of the first plate (21) and the third plate (23) on one side away from the second plate (22) are connected to the box body (40) via an adhesive layer (42).

10. The battery device according to claim 9, characterized in that: The box body (40) comprises a bottom plate (41), and the bottom plate (41) is connected to the first plate (21) and the third plate (23) via the adhesive layer (42).

11. The battery device according to claim 10, characterized in that: The bottom plate (41) is configured as a cold plate, and / or a cold plate is provided on a side of the bottom plate (41) facing the plurality of soft-pack battery cells (10), and the adhesive layer (42) is located between the cold plate and the plurality of soft-pack battery cells (10).

12. The battery device according to claim 10, characterized in that: The glue layer (42) comprises: a glue layer body (421) and a glue overflow portion (422), wherein the glue overflow portion (422) is located on a side of the glue layer body (421) facing the plurality of soft-pack battery cells (10), and is located between adjacent soft-pack battery cells (10), and / or between the soft-pack battery cells (10) and the first plate (21), and / or between the soft-pack battery cells (10) and the third plate (23).

13. The battery device according to claim 5, characterized in that: The flexible shell (11) has a side surface (111) opposite to the large surface of the electrode assembly (12) and a circumferential surface (112) avoiding the large surface, the side surface (111) and / or the circumferential surface (112) are provided with a weak portion (113), and the covering shell (20) has a pressure relief portion (221) at least partially opposite to the weak portion (113).

14. The battery device according to claim 13, characterized in that: The pressure relief portion (221) is formed on the second plate (22).

15. The battery device according to claim 14, characterized in that: The second plate (22) is spaced apart from a side of the circumferential surface (112) having the pressure relief portion (221) to define an exhaust passage (a).

16. The battery device according to claim 15, characterized in that: The second plate (22) is configured as a straight plate or a curved plate.

17. The battery device according to claim 15, characterized in that: There are a plurality of pressure relief portions (221), and the plurality of pressure relief portions (221) are arranged at intervals in the length direction and / or the width direction of the second plate (22).

18. The battery device according to any one of claims 1 to 17, characterized in that: The total power of the multiple soft-pack battery cells (10) in a single coating shell (20) is less than 0.9 kWh, and the energy density of the multiple soft-pack battery cells (10) in a single coating shell (20) satisfies: L≤450 Wh / L.

19. The battery device according to any one of claims 1 to 17, characterized in that: The total power of the multiple soft-pack battery cells (10) in a single coating shell (20) is less than 0.72 kWh, and the energy density of the multiple soft-pack battery cells (10) in a single coating shell (20) satisfies: 450 Wh / L<L≤600 Wh / L.

20. The battery device according to any one of claims 1 to 17, characterized in that: The total power of the multiple soft-pack battery cells (10) in a single coating shell (20) is less than 0.6 kWh, and the energy density of the multiple soft-pack battery cells (10) in a single coating shell (20) satisfies: 600 Wh / L<L≤700 Wh / L.

21. The battery device according to any one of claims 1 to 17, characterized in that: The total power of the multiple soft-pack battery cells (10) in a single coating shell (20) is less than 0.48 kWh, and the energy density of the multiple soft-pack battery cells (10) in the single coating shell (20) satisfies L>700 Wh / L.

22. The battery device according to any one of claims 1 to 17, characterized in that: The soft-pack battery cell (10) is any one of a lithium iron phosphate battery cell, a ternary lithium battery cell and a solid-state battery cell.

23. An electrical equipment, characterized in that: include: The battery device according to any one of claims 1 to 22.

24. The electrical equipment according to claim 23, characterized in that: The electrical equipment is a vehicle.

25. The electrical equipment according to claim 24, characterized in that: The battery device is integrated into the chassis of the vehicle, and the top plate of the box (40) of the battery device participates in defining the vehicle body floor.

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