Battery device and electric device

Abstract

The utility model relates to the technical field of batteries and discloses a battery device and a power utilization device.The battery device comprises a box body and a battery pack, the box body is provided with a containing cavity and a discharging cavity, the discharging cavity is arranged around the peripheral side of the containing cavity and communicates with the containing cavity through a communicating hole, and the box body comprises a top plate, a bottom plate and a frame; the frame is arranged around the bottom plate, an accommodating cavity is defined by the frame, the bottom plate and the top plate, the discharging cavity is formed in the frame, the communicating holes are formed in the inner circumferential wall of the frame, the battery pack is arranged in the accommodating cavity and comprises a shell and a plurality of soft package battery monomers accommodated in the shell, the shell is provided with a weak part, and the weak part is configured to be capable of releasing internal pressure of the soft package battery monomers. Therefore, the internal pressure of the soft package battery monomer is released, the heat spreading speed is slowed down, the use reliability of the battery device is improved, meanwhile, the energy density of the battery device can be considered to a certain extent, and the layout of the battery device is simplified.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery device and an electrical device. Background Art

[0002] In recent years, new energy vehicles have developed by leaps and bounds. As the power source of electric vehicles, battery devices play an irreplaceable and important role. Among them, battery devices use battery cells to store and provide electrical energy. Among them, soft-pack battery cells have been widely used due to their unique structure and advantages.

[0003] However, in the related art, the reliability of the battery device having the soft-pack battery cells needs to be further improved. Utility Model Content

[0004] The embodiments of the present application provide a battery device and an electrical device, which can release the internal pressure of a soft-pack battery cell and slow down the speed of heat spread, which is beneficial to improving the reliability of the battery device and can also take into account the energy density of the battery device to a certain extent.

[0005] In a first aspect, an embodiment of the present application provides a battery device, comprising: a box body, having a accommodating cavity and a discharge cavity, the discharge cavity being arranged around the outer peripheral side of the accommodating cavity, the discharge cavity being connected to the accommodating cavity through a connecting hole, the box body comprising a top plate, a bottom plate and a frame, the frame being arranged around the bottom plate and defining the accommodating cavity with the bottom plate and the top plate, the discharge cavity being formed in the frame, and the connecting hole being formed on the inner peripheral wall of the frame; a battery pack being arranged in the accommodating cavity and comprising a shell and a plurality of soft-pack battery cells accommodated in the shell, the shell having a weak portion, and the weak portion being configured to release the internal pressure of the soft-pack battery cells.

[0006] In the above technical solution, the receiving chamber is connected to the discharge chamber through the connecting hole, so that when the soft-pack battery cell is depressurized, the discharge will be discharged to the discharge chamber to release the pressure inside the soft-pack battery cell. Of course, the soft-pack battery cell can also release temperature to a certain extent, and the discharge entering the discharge chamber can be separated from the soft-pack battery cell in the receiving chamber to a certain extent, which is conducive to slowing down the speed of heat spread of the battery device and improving the reliability of the battery device. Moreover, the discharge chamber will not occupy the arrangement space provided by the receiving chamber for the soft-pack battery cell, which is convenient for the battery device to have a good energy density, and the layout is simple and easy to implement. In addition, by setting the box structure to include a top plate, a bottom plate and a frame, and making the frame and the top plate and the bottom plate define the receiving chamber, and the discharge chamber is formed in the frame, it is convenient to process and shape the receiving chamber and the discharge chamber, and it is convenient to set the discharge chamber around the receiving chamber, and at the same time, it is convenient to assemble the box.

[0007] In some embodiments, the shell has a U-shaped mounting cavity, the U-shaped mounting cavity has a first open side and a closed side arranged opposite to each other, and the closed side is provided with a weak portion; and / or, the U-shaped mounting cavity has a second open side and a third open side arranged opposite to each other, the second open side and the third open side are respectively provided with weak portions, and the pole ears of the soft-pack battery cell respectively extend out of the shell from the corresponding weak portions.

[0008] In the above technical solution, for the structure of the U-shaped installation cavity defined by the shell, the setting position of the weak part is relatively flexible, and a suitable setting position can be selected according to different requirements to better meet practical applications, and a suitable weak structure can also be selected according to the different setting positions of the weak part, so that the weak structure and its setting position can be well matched. It can be understood that when the second open side and the third open side are respectively provided with weak parts, the weak parts can be formed as avoidance openings or openings, which is convenient for simplifying the structure of the weak part and facilitating processing.

[0009] In some embodiments, the weak portion is configured as a pressure relief hole; or, the weak portion is configured as a notch; or, the weak portion is configured as a weakened portion. In the above technical solution, more options can be provided for the design of the weak portion to meet different usage requirements.

[0010] In some embodiments, the volume energy density of the soft-pack battery cell is ρ≥390Wh / L, and the opening area of ​​the connecting hole is S≥100cm 2 , the number of connecting holes n≥8; the volume energy density of the soft-pack battery monomer ρ<390Wh / L, then the opening area of ​​the connecting hole is 100cm 2 >S≥55cm 2 , the number of connecting holes 8>n≥4.

[0011] In the above technical solution, the opening area and number of the connecting holes can be set according to the volume energy density of the soft-pack battery cell, so that the opening area and number of the connecting holes are well matched with the volume energy density of the soft-pack battery cell. The openings of the connecting holes can not only meet the pressure relief requirements of the soft-pack battery cell, but also take into account the structural strength of the box body, and are not prone to excessive weakening of the box body.

[0012] In some embodiments, the battery device further includes: a first protective member disposed in the discharge chamber, the first protective member being opposite to the connecting hole and spaced apart, and the high temperature resistance of the first protective member being better than that of the box.

[0013] In the above technical solution, the setting of the first protective member will not affect the connection between the accommodating chamber and the discharge chamber through the connecting hole, and will not affect the pressure relief of the soft-pack battery cell. Moreover, since the first protective member is opposite to the connecting hole and has good high temperature resistance, at least part of the emissions discharged from the accommodating chamber through the connecting hole toward the discharge chamber will directly rush toward the first protective member. The first protective member can separate the emissions (for example, the high-temperature and high-pressure airflow generated inside the soft-pack battery cell when the soft-pack battery cell fails thermally, and even the airflow and electrolyte with sparks, etc.) from the inner wall of the discharge chamber to play a protective role, reduce the risk of damage to the box body due to the impact of the jet of high-temperature and high-pressure emissions, and help improve the structural stability and reliability of the box body.

[0014] In some embodiments, there are multiple connecting holes and they are spaced apart along the surrounding direction of the discharge cavity, and each connecting hole corresponds to a first protective member. In the above technical solution, the arrangement of the multiple connecting holes is relatively dispersed, which is convenient for adapting to the situation where the soft-pack battery cells at different positions have thermal runaway, and is conducive to making at least one of the multiple connecting holes have a discharge path with a suitable length corresponding to the soft-pack battery cells in thermal runaway, so as to take into account both the discharge smoothness and the discharge resistance; at the same time, since each connecting hole corresponds to a first protective member, no matter which connecting hole the discharge is discharged from to the discharge cavity, the corresponding first protective member can protect the box body and improve the reliability of the box body.

[0015] In some embodiments, on a preset plane, the orthographic projection of the hole wall of the communicating hole is within the orthographic projection range of the first protective member, and the preset plane is perpendicular to the axial direction of the communicating hole. In the above technical solution, on the preset plane, the covering area of ​​the first protective member is greater than or equal to the opening area of ​​the communicating hole, which can increase the protection area of ​​the first protective member, so that at least most of the emissions ejected from the communicating hole directly rush to the first protective member instead of the inner wall of the emission chamber, which is conducive to improving the protection effect of the first protective member on the box body and further reducing the impact of the emissions on the box body.

[0016] In some embodiments, on a preset plane, the minimum spacing x between the orthographic projection of the hole wall of the connecting hole and the outer contour of the orthographic projection of the first protective member is ≥5mm. In the above technical solution, by setting the minimum spacing x between the orthographic projection of the hole wall of the connecting hole and the outer contour of the orthographic projection of the first protective member on the preset plane to be ≥5mm, the difference between the covering area of ​​the first protective member and the opening area of ​​the connecting hole is further increased, and the protection area of ​​the first protective member is further increased, so that all the discharge ejected from the connecting hole directly rushes to the first protective member instead of the inner wall of the discharge chamber, thereby improving the protection effect of the box body.

[0017] In some embodiments, the first protective member is integrated into the box body; or, the first protective member is fixed to the inner wall of the discharge chamber. In the above technical solution, the first protective member is flexibly arranged, which is convenient for setting the connection mode between the first protective member and the box body according to different needs, so as to better meet the actual needs.

[0018] In some embodiments, the first protective member includes multiple protective layers arranged in sequence along the axial direction of the connecting hole, the multiple protective layers are made of different materials, and of the two adjacent protective layers, the high temperature resistance of the protective layer adjacent to the connecting hole is better than the high temperature resistance of the protective layer far from the connecting hole. In the above technical scheme, of the two adjacent protective layers, the protective layer adjacent to the connecting hole is closer to the emission and will preferentially withstand the high temperature jet impact of the emission. Then, in the above scheme, the high temperature resistance of the protective layer adjacent to the connecting hole is set to be better than the high temperature resistance of the protective layer far from the connecting hole, so as to appropriately reduce the high temperature resistance requirements of the protective layer far from the connecting hole under the premise of being able to reliably withstand the high temperature jet impact of the emission, which is conducive to appropriately reducing the material cost of the first protective member.

[0019] In some embodiments, the first protective member is a ceramic composite material member, a mica member, a glass fiber member, or a coating provided on the inner wall of the discharge cavity. In the above technical solution, these materials have excellent high temperature resistance and can withstand the impact of the discharge ejected from the connecting hole when the internal pressure of the soft-pack battery cell is released. At the same time, these materials have good processing performance and are easy to be reliably provided in the discharge cavity.

[0020] In some embodiments, the first protective member is formed into a sheet structure, and the thickness of the first protective member is t, 0.3mm≤t≤3mm. In the above technical solution, by setting the first protective member as a sheet structure, it is convenient to simplify the structure of the first protective member and facilitate processing. At the same time, the first protective member has a reasonable thickness, which is convenient to take into account both its own reliability and the protective effect on the box body, and will not occupy too much space in the discharge chamber.

[0021] In some embodiments, the two ends of the shell in the first horizontal direction are respectively provided with weak parts, and a storage groove is formed at the bottom of the shell corresponding to the end where the weak part is located, and the bottom wall of the storage groove is lower than the soft-pack battery cell. In the above technical solution, when the soft-pack battery cell is in thermal runaway, the liquid, particles, etc. in the discharge can be intercepted by the weak part, and the intercepted liquid, particles, etc. flow down to the storage groove for storage, and the discharge intercepted in the shell can be separated from the soft-pack battery cell. Then, these discharges are not easy to contact with the soft-pack battery cell and puncture the packaging body of the soft-pack battery cell, causing the insulation failure of the soft-pack battery cell, etc., which is conducive to improving the insulation reliability of the battery device during thermal runaway pressure relief discharge.

[0022] In some embodiments, the soft-pack battery cell is higher than the notch of the storage tank. In the above technical solution, by setting the soft-pack battery cell higher than the notch of the storage tank, it is helpful to increase the distance between the discharge in the storage tank and the soft-pack battery cell, further improve the storage tank's ability to separate the discharge in it from the soft-pack battery cell, reduce the probability of the discharge in the storage tank contacting the soft-pack battery cell, and help further improve the insulation reliability of the battery device during thermal runaway pressure relief discharge.

[0023] In some embodiments, an opening is formed at the bottom of the shell, and a supporting protrusion is convexly provided at the bottom of the accommodating cavity. The supporting protrusion is supported by the soft-pack battery cell and is glued and fixed to the soft-pack battery cell. The shell forms an accommodating groove with a notch facing downward between the two storage grooves. The opening is formed on the top wall of the accommodating groove. At least part of the supporting protrusion is accommodated in the accommodating groove and abuts against the groove wall of the accommodating groove. In the above technical solution, by providing the supporting protrusion and the accommodating groove, the groove wall of the storage groove can be matched with the supporting protrusion, so that the supporting protrusion can support the groove wall of the storage groove, which is beneficial to improving the structural stability of the storage groove. At the same time, the setting of the storage groove is beneficial to enhancing the structural strength of the bottom of the shell, and the setting of the supporting protrusion is beneficial to improving the structural stability of the opening and improving the setting stability of the battery pack.

[0024] In some embodiments, the battery device further includes: a pressure relief structure, which is arranged on one side of the box body in the second horizontal direction, or on the bottom side of the box body, the pressure relief structure is correspondingly connected to the discharge chamber, and the pressure relief structure and the connecting hole are arranged at intervals along the surrounding direction of the discharge chamber. In the above technical scheme, by arranging a pressure relief structure correspondingly connected to the discharge chamber, the internal pressure of the discharge chamber can be released, so that the emissions discharged when the soft-pack battery monomer is thermally runaway can be discharged out of the battery device through the pressure relief structure, which is conducive to slowing down the heat spread speed; moreover, the pressure relief structure and the connecting hole are arranged at intervals along the surrounding direction of the discharge chamber, so that the emissions at the connecting hole need to flow through a path after flowing into the discharge chamber and then flow to the pressure relief structure, so as to achieve smooth discharge, while taking into account a certain exhaust resistance, and improving the problem of easy fire due to too smooth discharge.

[0025] In some embodiments, the spacing y between the pressure relief structure and the connecting hole in the direction around the discharge chamber is ≥10 cm. In the above technical solution, by setting the spacing y between the pressure relief structure and the connecting hole in the direction around the discharge chamber to ≥10 cm, the discharge at the connecting hole needs to flow through a path of at least 10 cm in length after flowing into the discharge chamber and then flow to the pressure relief structure, so as to achieve smooth discharge while taking into account a certain exhaust resistance, which is conducive to further improving the problem of easy ignition due to too smooth discharge.

[0026] In some embodiments, the discharge chamber includes a first discharge section and a second discharge section that are connected in a bend, the second discharge section is connected to the connecting hole through the first discharge section, and the pressure relief structure is arranged on the second discharge section. In the above technical solution, the connecting hole is arranged on the first discharge section, the pressure relief structure is arranged on the second discharge section, and the first discharge section and the second discharge section are connected in a bend, so the discharge at the connecting hole needs to flow through a path after flowing into the discharge chamber and then flow to the pressure relief structure, and the discharge at the connecting hole needs to turn and flow to the pressure relief structure after flowing into the discharge chamber, so as to achieve smooth discharge while taking into account a certain exhaust resistance, and improve the problem of easy ignition due to too smooth discharge.

[0027] In some embodiments, when the volume energy density ρ of the soft-pack battery cell is ≥ 390Wh / L, the number of pressure relief structures is multiple; when the volume energy density ρ of the soft-pack battery cell is < 390Wh / L, the number of pressure relief structures is one. In the above technical solution, the number of pressure relief structures can be set according to the volume energy density of the soft-pack battery cell, so that the number of pressure relief structures and the volume energy density of the soft-pack battery cell are well matched, which can not only make the opening of the connecting hole meet the pressure relief requirements of the soft-pack battery cell, but also take into account the structural strength of the box body, and is not easy to cause excessive weakening of the box body.

[0028] In some embodiments, the frame includes a plurality of side beams connected end to end in sequence, and at least a portion of the plurality of side beams is hollow to define the discharge cavity. In the above technical solution, by setting the frame to include a plurality of side beams, the side beams participate in defining the discharge cavity, which facilitates the simplification of the structure of the frame and the processing and forming of the discharge cavity. At the same time, the provision of a plurality of side beams facilitates the flexible setting of the surrounding length of the discharge cavity.

[0029] In some embodiments, the discharge chamber includes a first discharge section and a second discharge section that are connected by bending, and the multiple side beams include two first side beams that are arranged opposite to each other along a first horizontal direction and two second side beams that are arranged opposite to each other along a third horizontal direction. Each first side beam is hollow to define a first discharge section, and each second side beam is hollow to define a second discharge section. The inner wall of each first side beam is formed with multiple connecting holes. In the above technical solution, the first discharge section is connected to the second discharge section by bending, and the second discharge section can be connected to the connecting hole through the first discharge section, so that a certain discharge resistance can be appropriately applied on the premise of achieving smooth discharge of the discharge, so as to improve the problem of easy ignition due to too smooth discharge, and the frame structure is simple and easy to process.

[0030] In some embodiments, a pressure relief structure is provided on the top of the shell, and the battery device further includes: a second protective member, which is provided between the top plate and the battery pack to separate the pressure relief structure from the top plate.

[0031] In the above technical solution, the provision of the second protective member will not affect the normal pressure relief release of the pressure relief structure, and at least part of the emissions discharged toward the pressure relief structure will directly rush toward the second protective member. The second protective member can separate the emissions from the pressure relief structure to play a protective role, reduce the pressure relief structure from being easily damaged by the impact of the jet of high-temperature and high-pressure emissions, and is beneficial to improving the pressure relief reliability and improving the reliability of the battery device.

[0032] In some embodiments, there are multiple battery packs, and the battery device also includes at least one of a first heat exchange element and a second heat exchange element, at least one of the first heat exchange element and the second heat exchange element is used for heat exchange with the soft-pack battery cell, the first heat exchange element is arranged between two adjacent battery packs, and the second heat exchange element is arranged between the battery pack and the box.

[0033] In some embodiments, the soft-pack battery cell is any one of a lithium iron phosphate battery cell, a ternary battery cell, and a solid-state battery cell. In the above technical solution, the use of the above types of soft-pack battery cells can provide more options for the design of the battery device to meet different usage requirements. Among them, the soft-pack battery cell is a lithium iron phosphate battery cell, which has the advantages of high reliability, long cycle life, light weight, large capacity, and low internal resistance; the soft-pack battery cell is a ternary battery cell, which has the advantages of high energy density and good electrochemical performance; the soft-pack battery cell is a solid-state battery cell, which has the advantages of high energy density and high reliability, light weight, and good high and low temperature performance.

[0034] In a second aspect, an embodiment of the present application provides an electrical device, comprising the above-mentioned battery device.

[0035] In the above technical solution, since the battery device has high reliability, the use of the battery device can improve the power consumption reliability of the power-consuming device. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0037] Figure 1 A schematic diagram of a structure in which the electric device provided in some embodiments of the present application is a vehicle;

[0038] Figure 2 An exploded view of the structure of a battery device provided in some embodiments of the present application;

[0039] Figure 3 An exploded view of the structure of a battery device provided in another embodiment of the present application;

[0040] Figure 4 for Figure 3 A schematic diagram of a battery pack shown in;

[0041] Figure 5 A schematic diagram of a battery device provided in some embodiments of the present application;

[0042] Figure 6 for Figure 5 Another schematic diagram of the battery device shown in;

[0043] Figure 7 A schematic diagram of a battery device provided in some other embodiments of the present application;

[0044] Figure 8 The graph is a result graph of pressure relief test on three different examples of battery devices;

[0045] Fig. 9 The graph is a result graph of pressure relief test on three different examples of battery devices;

[0046] Fig.10 The following is a graph showing the results of pressure relief tests on three different examples of battery devices.

[0047] Reference numerals:

[0048] Power device 1000, battery device 100, controller 200, motor 300,

[0049] Box body 1, accommodating chamber 1a, discharge chamber 1b, communicating hole 1c, supporting protrusion 1d, first discharge section 1e, second discharge section 1f, first box body 11, second box body 12, top plate 13, bottom plate 14, frame 15, side beam 151, first side beam 1511, second side beam 1512, battery pack 2, battery cell 20, shell 21, weak portion 210, U-shaped installation cavity 21a, first open side 21b, closed side 21c, second open side 21d, third open side 21e, opening 21f, storage slot 21g, accommodating slot 21h, first shell wall 211, second shell wall 212, third shell wall 213, first shell portion 214, second shell portion 215, third shell portion 216, flange portion 217, soft-pack battery cell 22, first protective member 3, pressure relief structure 4. DETAILED DESCRIPTION

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 the various components in the embodiments of the present application shown in the drawings are only exemplary and should not constitute any limitation on the present application. The "multiple" appearing in the present application refers to more than two (including two).

[0056] In the present application, the battery cells may include lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, lead storage batteries, etc., which are not limited in the embodiments of the present application. The battery cells may be cylindrical, flat, rectangular or other shapes, which are not limited in the embodiments of the present application.

[0057] The battery apparatus (Battery Apparatus) mentioned in the embodiments of the present application may refer to one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly (Battery Cell Assembly) may include multiple battery cells, and the multiple battery cells are connected in series, in parallel, or in mixed connection through a busbar. In some embodiments, the battery cell assembly (Battery Cell Assembly) is generally formed by arranging multiple battery cells.

[0058] As an example, the battery cell assembly may be a battery module, where a plurality of battery cells are arranged and fixed to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0059] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the housing. As an example, the battery cell assembly may be a battery pack, and the battery cell assembly may be accommodated in the housing by fixing the battery pack in the housing. As an example, the battery cell assembly may also be accommodated in the housing by directly fixing a plurality of battery cells to the housing. The housing may prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0060] The battery cell includes a shell, an electrode assembly and an electrolyte. The shell is used to accommodate the electrode assembly and the electrolyte. In the present application, the battery cell may be a soft-pack battery cell, which may refer to a battery cell using a soft outer packaging material as a shell. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as a positive electrode ear. Taking lithium-ion batteries as an example, the material of the positive electrode collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer serves as a negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that a large current passes without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together.

[0061] The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a winding structure or a stacked structure, but the embodiments of the present application are not limited thereto.

[0062] In recent years, new energy vehicles have developed by leaps and bounds, and battery devices, as the power source of electric vehicles, play an irreplaceable and important role. Among them, battery devices use battery cells to store and provide electrical energy, and among the many types of battery cells, soft-pack battery cells have been widely used due to their unique structure and advantages.

[0063] In the related art, in a general battery device, a plurality of soft-pack battery cells are usually installed side by side during production and assembly. When a soft-pack battery cell experiences thermal runaway, it is difficult to achieve timely pressure relief of the soft-pack battery cell, making the battery device prone to rapid heat spread and making it difficult to take into account the energy density of the battery device.

[0064] Based on the above considerations, a battery device is proposed, which includes a case and a battery pack. The case has a accommodating chamber and a discharge chamber, the discharge chamber is arranged around the outer peripheral side of the accommodating chamber, the discharge chamber is connected with the accommodating chamber through a connecting hole, the battery pack is arranged in the accommodating chamber, and includes a shell and a plurality of soft-pack battery cells accommodated in the shell, the shell has a weak portion, and the weak portion is configured to release the internal pressure of the soft-pack battery cells.

[0065] In the above technical solution, the accommodating chamber is connected to the discharge chamber through the connecting hole, so that when the soft-pack battery cell is depressurized, the discharge will be discharged into the discharge chamber to release the pressure inside the soft-pack battery cell. Of course, the soft-pack battery cell can also release temperature to a certain extent, and the discharge entering the discharge chamber can be separated from the soft-pack battery cell in the accommodating chamber to a certain extent, which is beneficial to slow down the speed of heat spread of the battery device and improve the reliability of the battery device. Moreover, the discharge chamber will not occupy the layout space provided by the accommodating chamber for the soft-pack battery cell, so that the battery device has a good energy density, and the layout is simple and easy to implement.

[0066] The battery device disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships, or aircraft. A power supply system of the electrical device can be composed of the battery device disclosed in the present application.

[0067] The embodiment of the present application provides an electric device using a battery device as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0068] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electric device 1000 of an embodiment of the present application. Figure 1 , Figure 1 The power consumption device 1000 provided for some embodiments of the present application is a schematic diagram of the structure of a vehicle. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. 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. The vehicle may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and driving the vehicle. Working power requirements.

[0069] In some embodiments of the present application, the battery device 100 can be used not only 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.

[0070] Please refer to Figure 2 , Figure 2The structural exploded diagram of the battery device 100 provided in some embodiments of the present application. The battery device 100 includes a box body 10 and a plurality of battery cells 20, and the battery cells 20 are used to be accommodated in the box body 10. Among them, the box body 10 is used to provide an assembly space for the battery cells 20, and the box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a first box body 11 and a second box body 12, and the first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cells 20. The second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure. The first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define the assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0071] In the battery device 100, multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that multiple battery cells 20 are connected in series and in parallel. Multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by multiple battery cells 20 is accommodated in the box 10; of course, the battery device 100 can also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery device 100 may also include other structures, for example, the battery device 100 may also include a busbar component for realizing electrical connection between multiple battery cells 20.

[0072] Please refer to Figure 2 , Figure 2 The structure of the battery device 100 provided in some embodiments of the present application is exploded. The battery device 100 includes multiple rows of battery cells 20, which are arranged along the length direction of the box body 10, and each row of battery cells 20 includes multiple battery cells 20 arranged along the width direction of the box body 10; or, multiple rows of battery cells 20 are arranged along the width direction of the box body 10, and each row of battery cells 20 includes multiple battery cells 20 arranged along the length direction of the box body 10.

[0073] Each battery cell 20 may be a secondary battery or a primary battery, wherein a secondary battery refers to a battery cell 20 that can be continuously used by activating the active material by charging after the battery cell is discharged; it may also 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-acid battery, etc., which is not limited in the embodiments of the present application. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes. For example, in Figure 2 In the figure, the battery cell 20 is in the shape of a rectangular parallelepiped.

[0074] For example, Figure 3 As shown, the battery cell 20 is roughly in the shape of a cuboid, and the height direction of the battery cell 20 is the third direction Z, the length direction of the battery cell 20 is the second direction Y, and the thickness direction of the battery cell is the first direction X. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. However, it is not limited to this. In other embodiments of the present application, the battery cell 20 may also be in the shape of a polygonal prism, a flat body, or other shapes.

[0075] Please refer to Figure 3 and Figure 5 In an embodiment of the present application, a battery device 100 includes a box body 1 and a battery pack 2 .

[0076] The box body 1 has a receiving chamber 1a and a discharge chamber 1b, the battery pack 2 is arranged in the receiving chamber 1a, the discharge chamber 1b is arranged around the outer peripheral side of the receiving chamber 1a, and the discharge chamber 1b is connected with the receiving chamber 1a through a connecting hole 1c; the battery pack 2 includes a shell 21 and a plurality of soft-pack battery cells 22 accommodated in the shell 21, the shell 21 has a weak portion 210, and the weak portion 210 is configured to release the internal pressure of the soft-pack battery cells 22. Exemplarily, the plurality of soft-pack battery cells 22 of the battery pack 2 can be arranged in sequence along the first direction.

[0077] It can be seen that the setting of the weak portion 210 can achieve pressure relief of the soft-pack battery cell 22. For example, the weak portion 210 is the weakest position on the shell 21. When the pressure inside the soft-pack battery cell 22 reaches a threshold, the pressure on the weak portion 210 reaches the maximum value it can withstand, so that the weak portion 210 is broken by the internal pressure of the soft-pack battery cell 22, and a channel connecting the inside and outside of the soft-pack battery cell 22 is formed at the corresponding position of the weak portion 210. The channel can release the pressure inside the soft-pack battery cell 22. The above threshold design varies according to different design requirements.

[0078] Then, when the soft-pack battery cell 22 releases pressure, the emissions will be discharged into the accommodating chamber 1a, and the accommodating chamber 1a is connected with the emission chamber 1b through the connecting hole 1c, and the emissions can flow into the emission chamber 1b through the connecting hole to release the pressure inside the soft-pack battery cell 22. Of course, the soft-pack battery cell 22 can also release temperature to a certain extent, and the emissions entering the emission chamber 1b can be separated from the soft-pack battery cell 22 in the accommodating chamber 1a to a certain extent, which is beneficial to slow down the speed of heat spread of the battery device 100.

[0079] In addition, since the discharge chamber 1b is arranged around the outer peripheral side of the accommodating chamber 1a, the discharge chamber 1b will not occupy the internal space of the accommodating chamber 1a, and the discharge chamber 1b will not occupy the arrangement space provided by the accommodating chamber 1a for the soft-pack battery cell 22, which is convenient for the battery device 100 to have a good energy density. Moreover, the above-mentioned arrangement of the discharge chamber 1b and the accommodating chamber 1a makes the relative position of the two relatively simple, which is convenient for the processing of the box body 1; and, by reasonably setting the specific structure of the discharge chamber 1b, it is beneficial to realize that the discharge chamber 1b can guide the discharge to a certain extent, so as to select a suitable position to discharge the discharge.

[0080] Of course, the box body 1 defines a discharge chamber 1b, which can not only discharge the exhaust discharged when the soft-pack battery cell 22 is depressurized, but also helps to make the part of the box body 1 corresponding to the discharge chamber 1b be constructed into a hollow structure, so as to reduce the material usage and weight of the box body 1 while maintaining the structural strength of the box body 1, which is beneficial to improve the energy density of the battery device 100 to a certain extent.

[0081] Exemplarily, the discharge chamber 1b is arranged around the outer peripheral side of the accommodating chamber 1a, and the outer peripheral side of the accommodating chamber 1a may include multiple sides. The discharge chamber 1b may be arranged on one of the multiple sides of the accommodating chamber 1a, or the discharge chamber 1b may be arranged on at least two of the multiple sides of the accommodating chamber 1a. The discharge chamber 1b may extend along a straight line or along a curve. For example, the discharge chamber 1b extends into a closed ring (such as Figure 5 As shown) or an open ring, for example, the discharge chamber 1b extends into an L-shape, a U-shape, or a C-shape. "Open ring" refers to: a ring with an opening, that is, a non-closed ring. "Ring" should be understood in a broad sense, that is, not limited to a "circular ring", for example, it can also be a "polygonal ring" and so on.

[0082] Please refer to Figure 3-Figure 6 The box body 1 includes a top plate 13, a bottom plate 14 and a frame 15. The frame 15 is arranged around the bottom plate 14, and the frame 15, the top plate 13 and the bottom plate 14 define a accommodating chamber 1a. The discharge chamber 1b is formed in the frame 15, and a communicating hole 1c is formed on the inner peripheral wall of the frame 15.

[0083] It can be understood that the frame 15 is a closed annular structure, and the inner peripheral wall of the frame 15 can participate in defining the peripheral wall of the accommodating chamber 1a, and can also participate in defining the peripheral wall of the discharge chamber 1b. The inner peripheral wall of the frame 15 can separate the accommodating chamber 1a and the discharge chamber 1b.

[0084] It can be seen that by setting the box body 1 to include a top plate 13, a bottom plate 14 and a frame 15, and making the frame 15, the top plate 13 and the bottom plate 14 define the accommodating chamber 1a, and the discharge chamber 1b is formed in the frame 15, it is convenient to process and shape the accommodating chamber 1a and the discharge chamber 1b, and it is convenient to realize that the discharge chamber 1b is arranged around the accommodating chamber 1a, and it is convenient to assemble the box body 1. It can be understood that the connection mode between the frame 15 and the top plate 13, and the connection mode between the frame 15 and the bottom plate 14 are not specifically limited in this application.

[0085] Please refer to Figure 3 and Figure 4 In some embodiments, the shell 21 has a U-shaped mounting cavity 21a, the U-shaped mounting cavity 21a has a first open side 21b and a closed side 21c that are oppositely arranged, and the closed side 21c is provided with a weak portion 210; and / or, the shell 21 has a U-shaped mounting cavity 21a, the U-shaped mounting cavity 21a has a second open side 21d and a third open side 21e that are oppositely arranged, and the second open side 21d and the third open side 21e are respectively provided with weak portions 210, and the tabs of the soft-pack battery cell 22 respectively extend out of the shell 21 from the corresponding weak portions 210.

[0086] It can be seen that for the structure of the U-shaped installation cavity 21a defined by the housing 21, the setting position of the weak portion 210 is relatively flexible, and a suitable setting position can be selected according to different requirements to better meet practical applications, and a suitable weak structure can also be selected according to the different setting positions of the weak portion 210, so that the weak structure and its setting position can be well matched. It can be understood that when the second open side 21d and the third open side 21e are respectively provided with a weak portion 210, the weak portion 210 can be formed as an avoidance opening or an open opening 21f, which is convenient for simplifying the structure of the weak portion 210 and facilitating processing.

[0087] Exemplarily, the weak portion 210 is provided on the closed side 21c, and the weak portion 210 may be a notch or a weakened portion; the weak portion 210 is provided on the second open side 21d and the third open side 21e, and the weak portion 210 may be a pressure relief hole.

[0088] exist Figure 4In the example, the shell 21 includes a first shell wall 211, a second shell wall 212 and a third shell wall 213, the first shell wall 211 and the third shell wall 213 are arranged opposite to each other along the width direction of the shell 21, the second shell wall 212 is bent and connected between the first shell wall 211 and the third shell wall 213, so that the first shell wall 211, the second shell wall 212 and the third shell wall 213 define a U-shaped installation cavity 21a, and the second shell wall 212 is connected to one end of the first shell wall 211 and the third shell wall 213 in the height direction of the shell 21, then the second shell wall 212 corresponds to the closed side 21c, the opening 21f of the shell 21 opposite to the second shell 21 corresponds to the first open side 21b, and the two sides of the shell 21 in the length direction correspond to the second open side 21d and the third open side 21e respectively. Among them, the width direction of the shell 21 can be the first direction, the height direction of the shell 21 can be the third direction, and the length direction of the shell 21 can be the second direction.

[0089] Of course, in other embodiments, the U-shaped mounting cavity 21a may not have the second open side 21d and the third open side 21e. In this case, the shell 21 is respectively closed on both sides corresponding to the second open side 21d and the third open side 21e, for example, by the first shell portion 214 described later.

[0090] In some embodiments, the weak portion 210 is configured as a pressure relief hole; or, the weak portion 210 is configured as a notch; or, the weak portion 210 is configured as a weakened portion. In the above technical solution, more options can be provided for the specific structural design of the weak portion 210 to meet different usage requirements.

[0091] In some embodiments, the volume energy density of the soft-pack battery cell 22 is ρ≥390Wh / L, and the opening area S of the connecting hole 1c is ≥100cm 2 , the number of connecting holes 1c n≥8; the volume energy density ρ of the soft-pack battery cell 22 is less than 390Wh / L, then the opening area of ​​the connecting hole 1c is 100cm 2 >S≥55cm 2 , the number of connecting holes 1c is 8>n≥4.

[0092] When the volume energy density ρ of the soft-pack battery cell 22 is greater than or equal to 390Wh / L, the energy released and the heat generated when the soft-pack battery cell 22 undergoes thermal runaway are relatively large, and the opening area S of the connecting hole 1c is ≥100cm 2, the number of openings n ≥ 8, so that the emissions of the soft-pack battery monomer 22 can be discharged in time through the connecting hole 1c, which is beneficial to reduce the impact on other soft-pack battery monomers 22 that have not experienced thermal runaway and slow down the spread of heat; when the energy density ρ of the soft-pack battery monomer 22 is less than 390Wh / L, the energy released and the heat generated when the soft-pack battery monomer 22 experiences thermal runaway are relatively small, and the opening area of ​​the connecting hole 1c is 100cm 2 >S≥55cm 2 The number of openings 8>n≥4, so that the discharge of the soft-pack battery cell 22 can be discharged in time through the connecting hole 1c, and at the same time it is beneficial to reduce the weakening of the box body 1.

[0093] It can be seen that in the above technical solution, the opening area and the number of openings of the connecting hole 1c can be set according to the volume energy density of the soft-pack battery cell 22, so that the opening area and the number of openings of the connecting hole 1c are well matched with the volume energy density of the soft-pack battery cell 22, which can not only make the opening of the connecting hole 1c meet the pressure relief requirements of the soft-pack battery cell 22, but also take into account the structural strength of the box body 1, and is not easy to cause excessive weakening of the box body 1.

[0094] Optionally, in the above solution, the plurality of communication holes 1c may be arranged at intervals along the extension direction of the discharge chamber 1b.

[0095] For example, Figure 8 As shown, three different examples are subjected to pressure relief tests. The three examples have the same number of connecting holes 1c, and the energy density ρ of the soft-pack battery monomer 22 is also the same, which is 380Wh / L. The difference between the three is that the opening area of ​​the connecting hole 1c is different. In Example 1, the opening area of ​​the connecting hole 1c is 40cm 2 In Example 2, the opening area of ​​the connecting hole 1c is 60 cm 2 In Example 3, the opening area of ​​the connecting hole 1c is 80 cm 2 ;from Figure 8 It can be seen that in Example 1, during the entire pressure relief process, the peak value of the internal pressure of the battery device 100 exceeds 20 kPa, while the corresponding peak values ​​of the internal pressures of Examples 2 and 3 do not exceed 20 kPa. Compared with Example 1, the battery device 100 is not prone to large swelling and deformation, and is not prone to airtightness problems of the battery device 100 due to the large internal pressure peak during the pressure relief process, that is, Examples 2 and 3 are better than Example 1. It can be understood that in the pressure relief test of the battery device 100, if the peak value of the internal pressure of the battery device 100 exceeds 20 kPa, it indicates that the battery device 100 is prone to large swelling and deformation, and is prone to airtightness problems later.

[0096] like Fig. 9As shown in the figure, three different examples are respectively subjected to pressure relief tests. The three examples have the same number of connecting holes 1c, and the opening area of ​​the connecting holes 1c is also the same, which is 60cm 2 The difference between the three is that the energy density ρ of the soft-pack battery cell 22 is different. The energy density ρ of the soft-pack battery cell 22 in Example 4 is 420Wh / L, the energy density ρ of the soft-pack battery cell 22 in Example 5 is 390Wh / L, and the energy density ρ of the soft-pack battery cell 22 in Example 6 is 360Wh / L; Fig. 9 It can be seen that in Example 4, during the entire pressure relief process, the internal pressure peak of the battery device 100 exceeds 20 kPa, while the corresponding internal pressure peaks of Examples 5 and 6 do not exceed 20 kPa. Compared with Example 4, the battery device 100 is not prone to large swelling deformation, and is not prone to airtightness problems of the battery device 100 due to the large internal pressure peak during the pressure relief process. That is, Examples 5 and 6 are better than Example 4.

[0097] like Fig.10 As shown, three different examples are subjected to pressure relief tests. The three examples have the same number of connecting holes 1c, and the energy density ρ of the soft-pack battery monomer 22 is also the same, which is 450Wh / L. The difference between the three is that the opening area of ​​the connecting hole 1c is different. In Example 7, the opening area of ​​the connecting hole 1c is 70cm 2 In Example 8, the opening area of ​​the connecting hole 1c is 100 cm 2 In Example 9, the opening area of ​​the connecting hole 1c is 130 cm 2 ;from Fig.10 It can be seen that in Example 7, during the entire pressure relief process, the internal pressure peak of the battery device 100 exceeded 20 kPa, while the corresponding internal pressure peaks of Examples 8 and 9 did not exceed 20 kPa. Compared with Example 7, the battery device 100 is not prone to large swelling deformation, and is not prone to airtightness problems of the battery device 100 due to the large internal pressure peak during the pressure relief process. That is, Examples 8 and 9 are better than Example 7.

[0098] Please refer to Figure 5 In some embodiments, the battery device 100 further includes a first protective member 3, which is disposed in the discharge chamber 1b, opposite to the connecting hole 1c, and spaced apart from the connecting hole 1c. The high temperature resistance of the first protective member 3 is better than that of the box body 1.

[0099] It can be seen that the setting of the first protective member 3 will not affect the connection between the accommodating chamber 1a and the discharge chamber 1b through the connecting hole 1c, and will not affect the pressure relief of the soft-pack battery cell 22. Moreover, since the first protective member 3 is opposite to the connecting hole 1c and the first protective member 3 has good high temperature resistance, at least part of the emissions discharged from the accommodating chamber 1a toward the discharge chamber 1b through the connecting hole 1c will directly rush toward the first protective member 3. The first protective member 3 can separate the high-temperature and high-pressure airflow, and even the airflow and electrolyte with sparks generated inside the soft-pack battery cell 22 when the soft-pack battery cell 22 fails thermally from the inner wall of the discharge chamber 1b to play a protective role, reduce the easy damage of the box body 1 due to the impact of the jet of high-temperature and high-pressure emissions, and help to improve the structural stability and reliability of the box body 1.

[0100] It can be understood that the first protection member 3 can be connected to the inner wall of the discharge chamber 1b.

[0101] Please refer to Figure 5 In some embodiments, there are multiple communicating holes 1c, and the multiple communicating holes 1c are arranged at intervals along the surrounding direction of the discharge chamber 1b, and each communicating hole 1c corresponds to a first protective member 3.

[0102] It can be seen that the arrangement of the multiple connecting holes 1c is relatively dispersed, which is convenient for adapting to the situation where the soft-pack battery cells 22 at different positions have thermal runaway, and is conducive to ensuring that at least one of the multiple connecting holes 1c has a discharge path of appropriate length corresponding to the soft-pack battery cells 22 with thermal runaway, so as to take into account both discharge smoothness and discharge resistance; at the same time, since each connecting hole 1c corresponds to a first protective member 3, no matter which connecting hole 1c the discharge is discharged from to the discharge chamber 1b, the corresponding first protective member 3 can protect the box body 1, thereby improving the reliability of the box body 1.

[0103] For example, Figure 5 As shown, the discharge chamber 1b includes a first discharge section 1e and a second discharge section 1f that are bent and connected, and a connecting hole 1c is provided on the first discharge section 1e, so that the second discharge section 1f is connected to the connecting hole 1c through the first discharge section 1e; further, there are two first discharge sections 1e and two second discharge sections 1f respectively, the two first discharge sections 1e are arranged opposite to each other, and the two second discharge sections 1f are arranged opposite to each other, each first discharge section 1e is connected to two second discharge sections 1f, so that the entire discharge chamber 1b is formed into a closed ring, and each first discharge section 1e is respectively formed with a plurality of connecting holes 1c spaced along its length direction, and no connecting hole 1c is provided on the second discharge section 1f.

[0104] Please refer to Figure 5In some embodiments, on a preset plane, the orthographic projection of the hole wall of the connecting hole 1c is located within the orthographic projection range of the first protective member 3, and the preset plane is perpendicular to the axial direction of the connecting hole 1c.

[0105] It can be seen that on the preset plane, the covering area of ​​the first protective member 3 is greater than or equal to the opening area of ​​the connecting hole 1c, which can increase the protection area of ​​the first protective member 3, so that at least most of the emissions ejected from the connecting hole 1c directly rush to the first protective member 3 instead of the inner wall of the emission chamber 1b, which is beneficial to improve the protection effect of the first protective member 3 on the box body 1 and further reduce the impact of the emissions on the box body 1.

[0106] It can be understood that in the embodiment of the present application, the opening shape of the connecting hole 1c may be the same as or different from the shape of the first protective member 3, or in other words, on a preset plane, the shape of the orthographic projection of the hole wall of the connecting hole 1c may be the same as or different from the shape of the orthographic projection outer contour of the first protective member 3.

[0107] Please refer to Figure 5 In some embodiments, on a preset plane, a minimum distance x between an orthographic projection of the hole wall of the communicating hole 1 c and an outer contour of an orthographic projection of the first protective member 3 is ≥5 mm.

[0108] In the above technical solution, by setting the minimum spacing x ≥ 5mm between the orthographic projection of the hole wall of the connecting hole 1c on the preset plane and the outer contour of the orthographic projection of the first protective member 3, the difference between the covering area of ​​the first protective member 3 and the opening area of ​​the connecting hole 1c can be further increased, and the protection area of ​​the first protective member 3 can be further increased, so that all the emissions ejected from the connecting hole 1c directly rush to the first protective member 3 instead of the inner wall of the discharge chamber 1b, thereby improving the protection effect of the box body 1.

[0109] In some embodiments, the first protective member 3 is integrated in the housing 1, for example, the first protective member 3 is integrally connected to the housing 1, in which case the first protective member 3 can be flush with the inner wall of the discharge chamber 1b, or the first protective member 3 can also protrude from the inner wall of the discharge chamber 1b; or, the first protective member 3 is fixed to the inner wall of the discharge chamber 1b, for example, the first protective member 3 and the housing 1 are separate parts, and the first protective member 3 is connected to the inner wall of the discharge chamber 1b by assembly connection means.

[0110] In the above technical solution, the first protective member 3 is flexibly arranged, which facilitates the connection between the first protective member 3 and the box body 1 to be arranged according to different requirements, thereby better meeting actual requirements.

[0111] It can be understood that when the first protective member 3 is fixed to the inner wall of the discharge chamber 1b, the connection method between the first protective member 3 and the box body 1 is not specifically limited, for example, the first protective member 3 is bonded to the inner wall of the discharge chamber 1b.

[0112] In some embodiments, the first protective member 3 includes multiple protective layers arranged in sequence along the axial direction of the connecting hole 1c. The materials of the multiple protective layers are different, and among two adjacent protective layers, the high temperature resistance of the protective layer adjacent to the connecting hole 1c is better than the high temperature resistance of the protective layer away from the connecting hole 1c.

[0113] It can be seen that, of the two adjacent protective layers, the protective layer adjacent to the connecting hole 1c is closer to the emissions and will preferentially withstand the high-temperature jet impact of the emissions. Therefore, in the above scheme, the high-temperature resistance of the protective layer adjacent to the connecting hole 1c is set to be better than the high-temperature resistance of the protective layer away from the connecting hole 1c. On the premise that it can reliably withstand the high-temperature jet impact of emissions, the high-temperature resistance requirements of the protective layer away from the connecting hole 1c can be appropriately reduced, which is conducive to appropriately reducing the material cost of the first protective component 3.

[0114] Of course, the first protective member 3 can also be constructed as a protective layer, which has a simple structure and is easy to process.

[0115] In some embodiments, the first protective member 3 is a ceramic composite material member such as a TC composite tape, a mica member, a glass fiber member, or a high-temperature resistant coating provided on the inner wall of the discharge chamber 1 b.

[0116] It can be seen that the above materials have excellent high temperature resistance and can withstand the impact of the exhaust ejected from the connecting hole 1c when the soft-pack battery cell 22 releases the internal pressure. At the same time, these materials have good processing performance and are easy to be reliably arranged in the exhaust cavity 1b.

[0117] Please refer to Figure 5 and Figure 6 In some embodiments, the first protective member 3 is formed into a sheet-like structure, and the thickness of the first protective member 3 is t, 0.3 mm≤t≤3 mm.

[0118] In the above technical solution, by setting the first protective member 3 as a sheet structure, the structure of the first protective member 3 is simplified and convenient for processing. At the same time, the first protective member 3 has a reasonable thickness, which is convenient for taking into account both its own reliability and the protective effect on the box body 1, and will not occupy too much space in the discharge chamber 1b.

[0119] For example, the thickness t of the first protective member 3 is 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2.2 mm, 2.7 mm, or 3 mm.

[0120] Please refer to Figure 7In some embodiments, the housing 21 has weak parts 210 at both ends in the first horizontal direction, and a storage slot 21g is formed at the bottom of the housing 21 corresponding to the end where the weak part 210 is located. Then, the housing 21 has storage slots 21g at both ends in the first horizontal direction, the notches of the storage slots 21g face upward, and the bottom wall of the storage slots 21g is lower than the soft-pack battery cell 22, that is, in the up-down direction, the bottom wall of the storage slots 21g is located below the soft-pack battery cell 22. For example, the first horizontal direction may be the second direction.

[0121] Therefore, when the soft-pack battery cell 22 thermally runs away, the liquid, particles, etc. in the emissions can be intercepted by the weak portion 210, and the intercepted liquid, particles, etc. flow downward to the storage groove 21g for storage, so that the emissions intercepted in the shell 21 can be separated from the soft-pack battery cell 22, and these emissions are not easy to contact with the soft-pack battery cell 22 and puncture the packaging body of the soft-pack battery cell 22, causing the insulation failure of the soft-pack battery cell 22, etc., which is beneficial to improve the insulation reliability of the battery device 100 during thermal runaway pressure relief and discharge.

[0122] For example, Figure 7 As shown, for a single storage slot 21g, the storage slot 21g can be spaced apart at one end of the soft-pack battery cell 22 in the first horizontal direction; the present application does not make any specific restrictions on the formation method of the storage slot 21g, for example, the end of the shell 21 in the first horizontal direction can be bent multiple times to define a storage slot 21g with the notch facing upward.

[0123] Optionally, both ends of the shell 21 in the first horizontal direction may correspond to the second open side 21d and the third open side 21e described above, respectively, and the weak portions 210 at both ends of the shell 21 in the first horizontal direction are not limited by defining the direction in which the shell 21 is opened.

[0124] Please refer to Figure 7 In some embodiments, the soft-pack battery cell 22 is higher than the notch of the storage groove 21g.

[0125] In the above technical solution, by setting the notch of the soft-pack battery cell 22 higher than the storage groove 21g, it is beneficial to increase the distance between the discharge in the storage groove 21g and the soft-pack battery cell 22, further improve the storage groove 21g's ability to separate the discharge therein from the soft-pack battery cell 22, and reduce the probability of contact between the discharge in the storage groove 21g and the soft-pack battery cell 22, which is beneficial to further improve the insulation reliability of the battery device 100 during thermal runaway pressure relief discharge.

[0126] Please refer to Figure 7In some embodiments, an opening 21f is formed at the bottom of the shell 21, a supporting protrusion 1d is protruded from the bottom of the accommodating cavity 1a, the supporting protrusion 1d is supported by the soft-pack battery cell 22 and the supporting protrusion 1d is glued and fixed to the soft-pack battery cell 22, and a accommodating groove 21h with a notch facing downward is formed in the shell 21 between the two storage grooves 21g, the opening 21f is formed on the top wall of the accommodating groove 21h, at least a portion of the supporting protrusion 1d is accommodated in the accommodating groove 21h, and the supporting protrusion 1d is stopped against the groove wall of the accommodating groove 21h.

[0127] Exemplarily, the shell 21 may include a first shell portion 214, a second shell portion 215 and a third shell portion 216 which are bent and connected in sequence. The second shell portion 215 can define the bottom wall of the storage groove 21g. The first shell portion 214 and the third shell wall 213 respectively define the side walls of the storage groove 21g. The third shell portion 216 is located on the side of the first shell portion 214 facing the soft-pack battery cell 22. The end of the third shell portion 216 away from the first shell wall 211 has a flange portion 217, and the flange portion 217 participates in defining the top wall of the accommodating groove 21h. The third shell portion 216 participates in defining the side walls of the accommodating groove 21h. The accommodating groove 21h is located between two flange portions 217 arranged opposite to each other along the first horizontal direction. Each flange portion 217 is built to stop at the top of the support protrusion 1d; further, each third shell wall 213 stops at the outer peripheral wall of the support protrusion 1d. It can be seen that the provision of the supporting protrusion 1d is conducive to raising the height position of the soft-pack battery cell 22 so as to increase the distance between the notch of the storage groove 21g and the soft-pack battery cell 22 in the up and down direction.

[0128] Optionally, the adhesive connection between the supporting protrusion 1 d and the soft-pack battery cell 22 may be provided at the opening 21 f of the housing 21 .

[0129] In the above technical solution, by setting the supporting protrusion 1d and the accommodating groove 21h, the groove wall of the storage groove 21g can be matched with the supporting protrusion 1d, so that the supporting protrusion 1d can support the groove wall of the storage groove 21g, which is beneficial to improving the structural stability of the storage groove 21g. At the same time, the setting of the storage groove 21g is beneficial to enhancing the structural strength of the bottom of the shell 21, and the setting of the supporting protrusion 1d is beneficial to improving the structural stability of the opening 21f and improving the setting stability of the battery pack 2.

[0130] Please refer to Figure 5 In some embodiments, the battery device 100 further includes a pressure relief structure 4, which is disposed on one side of the box body 1 in the second horizontal direction, or on the bottom side of the box body 1, and the pressure relief structure 4 is correspondingly connected to the discharge chamber 1b, and the pressure relief structure 4 and the connecting hole 1c are spaced apart in the surrounding direction of the discharge chamber 1b. For example, the first horizontal direction may be the first direction.

[0131] Exemplarily, when the internal pressure or temperature of the discharge chamber 1b reaches a predetermined threshold, the pressure relief structure 4 is actuated to release the internal pressure or temperature. When the internal pressure or temperature of the discharge chamber 1b reaches a predetermined threshold, the pressure relief structure 4 performs an action or a weak structure provided in the pressure relief structure 4 is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released; the threshold design varies according to different design requirements.

[0132] In the above technical solution, by setting a pressure relief structure 4 corresponding to the discharge chamber 1b, the internal pressure of the discharge chamber 1b can be released, so that the exhaust discharged when the soft-pack battery cell 22 is in thermal runaway can be discharged from the battery device 100 through the pressure relief structure 4, which is conducive to slowing down the heat spread speed; moreover, the pressure relief structure 4 and the connecting hole 1c are arranged at intervals along the surrounding direction of the discharge chamber 1b, so that the exhaust at the connecting hole 1c needs to flow through a path after flowing into the discharge chamber 1b and then flow to the pressure relief structure 4, so as to achieve smooth discharge, while taking into account a certain exhaust resistance, and improving the problem of easy fire due to too smooth discharge. In addition, the setting position of the pressure relief structure 4 has a certain flexibility to better meet the actual differentiated needs.

[0133] In the embodiment of the present application, the second horizontal direction is parallel to or intersects with the first horizontal direction.

[0134] Please refer to Figure 5 In some embodiments, the distance y between the pressure relief structure 4 and the connecting hole 1c in the direction around the discharge chamber 1b is ≥ 10 cm. In other words, the discharge at the connecting hole 1c flows through a path of at least 10 cm in length when it flows to the position of the pressure relief structure 4.

[0135] In the above technical solution, by setting the spacing y between the pressure relief structure 4 and the connecting hole 1c in the direction around the discharge chamber 1b to be ≥10cm, the emissions at the connecting hole 1c need to flow through a path of at least 10cm in length after flowing into the discharge chamber 1b and then flow to the pressure relief structure 4, so as to achieve smooth discharge while taking into account a certain exhaust resistance, which is conducive to further improving the problem of easy ignition due to too smooth discharge.

[0136] It can be understood that when there are multiple pressure relief structures 4, the distance between each pressure relief structure 4 and any connecting hole 1c in the surrounding direction of the discharge chamber 1b is greater than or equal to 10 cm.

[0137] Please refer to Figure 5 In some embodiments, the discharge chamber 1b includes a first discharge section 1e and a second discharge section 1f that are connected by bending, the second discharge section 1f is connected to the connecting hole 1c through the first discharge section 1e, and the pressure relief structure 4 is provided on the second discharge section 1f. Thus, the discharge at the connecting hole 1c can first flow to the first discharge section 1e, then flow to the second discharge section 1f after turning, and be released through the pressure relief structure 4.

[0138] In the above technical solution, the connecting hole 1c is provided on the first discharge section 1e, the pressure relief structure 4 is provided on the second discharge section 1f, and the first discharge section 1e and the second discharge section 1f are connected by bending. Then, the discharge at the connecting hole 1c needs to flow through a path after flowing into the discharge chamber 1b and then flow to the pressure relief structure 4, and the discharge at the connecting hole 1c needs to turn and then flow to the pressure relief structure 4 after flowing into the discharge chamber 1b, so as to achieve smooth discharge while taking into account a certain exhaust resistance, thereby improving the problem of easy ignition due to excessively smooth discharge.

[0139] In some embodiments, when the volume energy density ρ of the soft-pack battery cell 22 is ≥390Wh / L, the number of the pressure relief structures 4 is multiple; when the volume energy density ρ of the soft-pack battery cell 22 is <390Wh / L, the number of the pressure relief structures 4 is one.

[0140] When the volume energy density ρ of the soft-pack battery cell 22 is greater than or equal to 390Wh / L, the energy released and the heat generated when the soft-pack battery cell 22 has thermal runaway are relatively large, and there are multiple pressure relief structures 4, which can appropriately increase the discharge area and facilitate timely release of the internal pressure of the discharge chamber 1b; when the energy density ρ of the soft-pack battery cell 22 is less than 390Wh / L, the energy released and the heat generated when the soft-pack battery cell 22 has thermal runaway are relatively small, and there is only one pressure relief structure 4, so that the emissions from the soft-pack battery cell 22 can be discharged in time through the pressure relief structure 4, which is also beneficial to reduce the number of pressure relief structures 4 and simplify the structure of the battery device 100.

[0141] It can be seen that in the above technical solution, the number of pressure relief structures 4 can be set according to the volume energy density of the soft-pack battery cell 22, so that the number of pressure relief structures 4 and the volume energy density of the soft-pack battery cell 22 are well matched, which can not only make the opening of the connecting hole 1c meet the pressure relief requirements of the soft-pack battery cell 22, but also take into account the structural strength of the box body 1, and is not easy to cause excessive weakening of the box body 1.

[0142] Please refer to Figure 3 and Figure 5 In some embodiments, the frame 15 includes a plurality of side beams 151 connected end to end in sequence, and at least part of the plurality of side beams 151 is hollow to define the discharge chamber 1b, then at least one of the plurality of side beams 151 participates in defining the discharge chamber 1b.

[0143] In the above technical solution, the frame 15 includes multiple side beams 151, and the side beams 151 participate in defining the discharge chamber 1b, which is convenient for simplifying the structure of the frame 15 and facilitating the processing and forming of the discharge chamber 1b. At the same time, the setting of multiple side beams 151 facilitates the flexible setting of the surrounding length of the discharge chamber 1b.

[0144] Exemplarily, the frame 15 includes four side beams 151 connected end to end in sequence, and each side beam 151 is hollow, so that each side beam 151 participates in defining a part of the discharge chamber 1b.

[0145] Please refer to Figure 5 In some embodiments, the discharge chamber 1b includes a first discharge section 1e and a second discharge section 1f that are bent and connected, and the multiple side beams 151 include two first side beams 1511 that are oppositely arranged along a first horizontal direction and two second side beams 1512 that are oppositely arranged along a third horizontal direction. Each first side beam 1511 is hollow to define the first discharge section 1e, and each second side beam 1512 is hollow to define the second discharge section 1f. The inner wall of each first side beam 1511 is formed with multiple connecting holes 1c.

[0146] It can be seen that the first discharge section 1e is connected to the second discharge section 1f by bending, and the second discharge section 1f can be connected to the connecting hole 1c through the first discharge section 1e, so that on the premise of achieving smooth discharge of emissions, a certain discharge resistance can be appropriately applied to improve the problem of easy ignition due to too smooth discharge, and the frame 15 has a simple structure and is easy to process.

[0147] It can be understood that in the embodiment of the present application, there is no specific limitation on the opening shape of the connecting hole 1c. For example, the connecting hole 1c can be a circular hole, a polygonal hole, an elliptical hole, etc.

[0148] In some embodiments, a pressure relief structure 4 is disposed on the top of the housing 21 , and the battery device 100 further includes a second protective member disposed between the top plate 13 and the battery pack 2 to separate the pressure relief structure 4 from the top plate 13 .

[0149] In the above technical solution, the provision of the second protective member will not affect the normal pressure relief of the pressure relief structure 4, and at least part of the emissions discharged toward the pressure relief structure 4 will directly rush toward the second protective member, and the second protective member can separate the emissions from the pressure relief structure 4 to play a protective role, reduce the pressure relief structure 4 from being easily damaged by the impact of the injection of high-temperature and high-pressure emissions, and help improve the reliability of pressure relief and the reliability of the battery device 100. In addition, if the battery device 100 is used in a vehicle, if the battery device 100 is provided at the bottom of the vehicle, the provision of the second protective member can better isolate the injected emissions from the driver and passengers, and improve the driving performance.

[0150] In some embodiments, there are multiple battery groups 2, and the battery device 100 also includes at least one of a first heat exchange element and a second heat exchange element, and the at least one of the first heat exchange element and the second heat exchange element is used for heat exchange with the soft-pack battery cell 22; wherein the first heat exchange element is arranged between two adjacent battery groups 2, and the second heat exchange element is arranged between the battery group 2 and the box body 1.

[0151] It can be seen that the first heat exchange element is arranged between two adjacent battery groups 2, for example, the first heat exchange element is arranged between the shells 21 of two adjacent battery groups 2, so that the first heat exchange element can perform heat exchange with the two adjacent battery groups 2, so that the operating temperature of the multiple battery groups 2 can be maintained within a relatively appropriate range, which helps to reduce the temperature difference between the battery groups 2 and is convenient for improving the working stability of the battery device 100. In addition, by arranging the first heat exchange element between two adjacent battery groups 2, it is convenient to make full use of the space inside the battery device 100, improve the space utilization rate, and facilitate the miniaturization design of the battery device 100; the second heat exchange element is arranged between the battery group 2 and the box body 1, which is also convenient for maintaining the temperature of the soft-pack battery cell 22 within a suitable range, improving the reliability of the battery device 100, and heat transfer through the second heat exchange element can further enhance the thermal management capability of the battery device 100, which helps to keep the internal temperature of the battery device 100 within a reasonable range when the battery device 100 is working, thereby improving the working efficiency and stability of the battery device 100.

[0152] Exemplarily, a second heat exchange element may be provided between the top plate 13 of the box body 1 and the battery pack 2, and / or a second heat exchange element may be provided between the bottom plate 14 of the box body 1 and the battery pack 2, and / or a second heat exchange element may be provided between at least one side beam 151 in the frame 15 of the box body 1 and the battery pack 2.

[0153] In some embodiments of the present application, the soft-pack battery cell 22 is a ternary battery cell, and the shell 21 of the battery pack 2 wraps multiple soft-pack battery cells 22 around three peripheral sides of the multiple soft-pack battery cells 22 of the battery pack 2, and the shell wall of the shell 21 arranged opposite to its open end is provided with a weak portion 210.

[0154] In the above technical solution, the weak portion 210 can guide the exhausted gas to directional pressure relief when the ternary battery cell undergoes thermal runaway expansion and exhaust pressure relief, thereby reducing the risk of gas chaos affecting the surrounding ternary battery cells, and also reducing the risk of serious thermal runaway of the battery pack 2 composed of the ternary battery cells, which is beneficial to the thermal runaway management of the battery pack 2 and improves the reliability of the battery pack 2 composed of the ternary battery cells.

[0155] In some embodiments of the present application, the soft pack battery cell 22 is any one of a lithium iron phosphate battery cell, a ternary battery cell and a solid-state battery cell. Among them, the solid-state battery cell can 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 can also be a semi-solid-state battery cell or a fully solid-state battery cell.

[0156] In the above technical solution, the soft-pack battery cell 22 adopts the above types to provide more options for the design of the battery device 100 to meet different usage requirements. Among them, the soft-pack battery cell 22 is a lithium iron phosphate battery cell, which has the advantages of high reliability, long cycle life, light weight, large capacity, and low internal resistance; the soft-pack battery cell 22 is a ternary battery cell, which has the advantages of high energy density and good electrochemical performance; the soft-pack battery cell 22 is a solid-state battery cell, which has the advantages of high energy density and high reliability, light weight, and good high and low temperature performance.

[0157] In some embodiments of the present application, the soft-pack battery cell 22 is a lithium iron phosphate battery cell, and in the positive electrode material of the soft-pack battery cell 22, the usage ratio of the positive electrode active material, the binder, and the conductive agent is 96: (1-3): (1-3); the soft-pack battery cell 22 is a ternary battery cell, and in the positive electrode material of the soft-pack battery cell 22, the usage ratio of the positive electrode active material, the binder, and the conductive agent is 96: (2-3): (1-2).

[0158] In the above technical solution, when the soft-pack battery cell 22 is a lithium iron phosphate battery cell, a high proportion of positive electrode active material means that more substances capable of 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 22 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 reducing the risk of active material shedding and electrode pulverization during charging and discharging, and extending the cycle life of the battery device 100.

[0159] In some embodiments, the positive electrode of the soft-pack battery cell 22 may be a positive electrode sheet, which may include a positive electrode collector and a positive electrode film layer disposed on at least one surface of the positive electrode collector, wherein the positive electrode film layer includes a positive electrode active material.

[0160] 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.

[0161] 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.).

[0162] As an example, when the soft-pack battery cell 22 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 22. 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.

[0163] 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.

[0164] Layered transition metal oxides include those of the general formula Li a Ni b Co c M d O e A f At least one 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.

[0165] 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 NCM333 )、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.

[0166] When the soft-pack battery cell 22 of the embodiment of the present application is a sodium ion battery, the positive electrode active material may include but is not limited to at least one of sodium-containing transition metal oxides, polyanion materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian blue materials.

[0167] 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 Y3-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.

[0168] 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.

[0169] The charge and discharge process of the soft-pack battery cell 22 is accompanied by the deintercalation and consumption of active ions such as Li. The molar content of Li is different when the soft-pack battery cell 22 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, and the molar content of Li may change after the charge and discharge cycle.

[0170] 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.

[0171] In the embodiments of the present application, the content of elements in the positive electrode active material has 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 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.

[0172] 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.

[0173] 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%.

[0174] 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%.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.).

[0179] As an example, the negative electrode active material may adopt the negative electrode active material for soft-pack battery cells 22 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.

[0180] 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 increase the energy density of the soft-pack battery cell 22.

[0181] 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 22 system, when the mass content of silicon is within the above range, the energy density of the soft-pack battery cell 22 can be improved.

[0182] 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.

[0183] 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%.

[0184] 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%.

[0185] 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%.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] In some embodiments, the isolation membrane may include a porous base membrane and a coating disposed on at least one side of the porous base membrane, and the coating may include at least one of inorganic particles or organic particles. The porous base membrane may include one or more of polyethylene and polypropylene.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] In some embodiments, the pouch cell 22 further includes an electrolyte.

[0195] During the charge and discharge process of the battery cell, the active ions are embedded and released back and forth between the positive electrode and the negative electrode, and the electrolyte plays the role of conducting the active ions between the positive electrode and the negative electrode. The embodiment of the present application has no particular restriction on the type of electrolyte, which can be selected according to actual needs. The electrolyte includes an electrolyte salt and a solvent. The types of electrolyte salts and solvents are not specifically limited and can be selected according to actual needs.

[0196] 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.

[0197] 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.

[0198] It can be understood that when the soft-pack battery cell 22 is a lithium iron phosphate battery cell, in the positive electrode material of the soft-pack battery cell 22, the positive electrode active material accounts for 96 parts of the total weight of the positive electrode material, the binder accounts for 1 to 3 parts of the total weight of the positive electrode material (for example, it can 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 can include but is not limited to 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, etc.).

[0199] For example, when the soft-pack battery cell 22 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.

[0200] When the soft-pack battery cell 22 is a ternary battery cell, in the positive electrode material of the soft-pack battery cell 22, the positive electrode active material accounts for 96 parts of the total weight of the positive electrode material, the binder accounts for 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 lithium oxide system, etc.

[0201] 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.

[0202] In a second aspect, an embodiment of the present application provides an electrical device 1000 , including the above-mentioned battery device 100 , and the battery device 100 is used to provide electrical energy.

[0203] In the above technical solution, since the battery device 100 has high reliability, the use of the battery device 100 can improve the power consumption reliability of the power consumption device 1000.

[0204] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0205] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery device, characterized in that: include: A box body, having a receiving cavity and a discharge cavity, wherein the discharge cavity is arranged around the outer peripheral side of the receiving cavity, and the discharge cavity is communicated with the receiving cavity through a communication hole, wherein the box body comprises a top plate, a bottom plate and a frame, wherein the frame is arranged around the bottom plate and defines the receiving cavity with the bottom plate and the top plate, wherein the discharge cavity is formed in the frame, and the communication hole is formed on the inner peripheral wall of the frame; The battery pack is arranged in the accommodation cavity and comprises a shell and a plurality of soft-pack battery cells accommodated in the shell, wherein the shell has a weak portion configured to release the internal pressure of the soft-pack battery cells.

2. The battery device according to claim 1, characterized in that: The housing has a U-shaped mounting cavity. The U-shaped installation cavity has a first open side and a closed side that are arranged opposite to each other, and the closed side is provided with the weak portion; and / or, The U-shaped installation cavity has a second open side and a third open side that are arranged opposite to each other, the second open side and the third open side are respectively provided with the weak parts, and the tabs of the soft-pack battery cell extend out of the shell from the corresponding weak parts respectively.

3. The battery device according to claim 1, characterized in that: The weak portion is configured as a pressure relief hole; or, the weak portion is configured as a notch; or, the weak portion is configured as a weakened portion.

4. The battery device according to claim 1, characterized in that: The volume energy density of the soft-pack battery monomer is ρ≥390Wh / L, and the opening area of ​​the connecting hole is S≥100cm 2 , the number of the communicating holes n≥8; The volume energy density of the soft-pack battery monomer is ρ<390Wh / L, and the opening area of ​​the connecting hole is 100cm 2 >S≥55cm 2 , the number of the connecting holes is 8>n≥4.

5. The battery device according to claim 1, characterized in that: Also includes: The first protective member is arranged in the discharge chamber, the first protective member is opposite to the connecting hole and is arranged at a distance, and the high temperature resistance of the first protective member is better than that of the box body.

6. The battery device according to claim 5, characterized in that: There are a plurality of communicating holes which are arranged at intervals along the surrounding direction of the discharge chamber, and each communicating hole corresponds to one of the first protective members.

7. The battery device according to claim 5, characterized in that: On a preset plane, the orthographic projection of the hole wall of the communicating hole is located within the orthographic projection range of the first protective member, and the preset plane is perpendicular to the axial direction of the communicating hole.

8. The battery device according to claim 7, characterized in that: On the preset plane, a minimum distance x between an orthographic projection of the hole wall of the communicating hole and an outer contour of an orthographic projection of the first protective member is ≥5 mm.

9. The battery device according to claim 5, characterized in that: The first protective element is integrated into the box body; or, The first protection member is fixedly arranged on the inner wall of the discharge chamber.

10. The battery device according to claim 5, characterized in that: The first protective member includes multiple protective layers arranged in sequence along the axial direction of the connecting hole. The materials of the multiple protective layers are different, and among two adjacent protective layers, the high temperature resistance of the protective layer adjacent to the connecting hole is better than that of the protective layer far away from the connecting hole.

11. The battery device according to claim 5, characterized in that: The first protective member is a ceramic composite material member, a mica member, a glass fiber member, or a coating provided on the inner wall of the discharge cavity.

12. The battery device according to claim 5, characterized in that: The first protection member is formed into a sheet-like structure, and a thickness of the first protection member is t, 0.3 mm≤t≤3 mm.

13. The battery device according to any one of claims 1 to 12, characterized in that: The two ends of the shell in the first horizontal direction are respectively provided with the weak parts, and a storage groove is formed at the bottom of the shell corresponding to the end where the weak part is located, and the bottom wall of the storage groove is lower than the soft-pack battery cell.

14. The battery device according to claim 13, characterized in that: The soft-pack battery cell is higher than the notch of the storage slot.

15. The battery device according to claim 13, characterized in that: An opening is formed at the bottom of the shell, a supporting protrusion is convexly provided at the bottom of the accommodating cavity, the supporting protrusion is supported by the soft-pack battery cell and is glued and fixed to the soft-pack battery cell, a accommodating groove with a notch facing downward is formed in the shell between the two storage grooves, the opening is formed on the top wall of the accommodating groove, at least a portion of the supporting protrusion is accommodated in the accommodating groove, and stops at the groove wall of the accommodating groove.

16. The battery device according to any one of claims 1 to 12, characterized in that: Also includes: The pressure relief structure is arranged on one side of the box body in the second horizontal direction, or on the bottom side of the box body. The pressure relief structure is correspondingly connected to the discharge chamber. The pressure relief structure and the connecting hole are spaced apart along the surrounding direction of the discharge chamber.

17. The battery device according to claim 16, characterized in that: The distance y between the pressure relief structure and the communicating hole in the surrounding direction of the discharge chamber is ≥10 cm.

18. The battery device according to claim 16, characterized in that: The discharge chamber comprises a first discharge section and a second discharge section which are connected in a bent manner. The second discharge section is connected to the connecting hole through the first discharge section. The pressure relief structure is arranged on the second discharge section.

19. The battery device according to claim 16, characterized in that: When the volume energy density ρ of the soft-pack battery cell is ≥390Wh / L, the number of the pressure relief structures is multiple; When the volume energy density ρ of the soft-pack battery cell is less than 390Wh / L, the number of the pressure relief structure is one.

20. The battery device according to any one of claims 1 to 12, characterized in that: The frame includes a plurality of side beams connected end to end in sequence, and at least a portion of the plurality of side beams is hollow to define the discharge cavity.

21. The battery device according to claim 20, characterized in that The discharge chamber includes a first discharge section and a second discharge section that are bent and connected, and the multiple side beams include two first side beams that are relatively arranged along a first horizontal direction and two second side beams that are relatively arranged along a third horizontal direction, each of the first side beams is hollow to define the first discharge section, each of the second side beams is hollow to define the second discharge section, and the inner wall of each of the first side beams is formed with multiple connecting holes.

22. The battery device according to claim 21, characterized in that A pressure relief structure is provided on the top of the housing, and the battery device further comprises: A second protective member is disposed between the top plate and the battery pack to separate the pressure relief structure from the top plate.

23. The battery device according to any one of claims 1 to 12, characterized in that: The battery pack is a plurality of groups, and the battery device further includes at least one of a first heat exchange member and a second heat exchange member, wherein the at least one of the first heat exchange member and the second heat exchange member is used for heat exchange with the soft pack battery cell. The first heat exchange component is arranged between two adjacent groups of battery packs, and the second heat exchange component is arranged between the battery pack and the box.

24. The battery device according to any one of claims 1 to 12, characterized in that: The soft-pack battery cell is any one of a lithium iron phosphate battery cell, a ternary battery cell and a solid-state battery cell.

25. An electrical device, characterized in that: Comprising a battery device according to any one of claims 1-24.

Images