Battery device and electric device

Abstract

A battery device and an electric device. The battery device comprises a case and a battery pack, wherein the case is provided with an accommodating cavity and a discharge cavity, the discharge cavity being arranged around the outer peripheral side of the accommodating cavity, and the discharge cavity being in communication with the accommodating cavity by means of a communication hole; and the battery pack is arranged in the accommodating cavity and comprises a casing and a plurality of pouch battery cells accommodated inside the casing, the casing having a weak portion, which is configured to release the internal pressure of the pouch battery cells.

Description

Battery devices and electrical appliances Technical Field

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

[0002] In recent years, new energy vehicles have experienced rapid development, and battery devices, as the power source of electric vehicles, play an irreplaceable and crucial role. Battery devices utilize individual battery cells to store and provide electrical energy, and pouch cells, due to their unique structure and advantages, have been widely used.

[0003] However, the reliability of battery devices with pouch cells needs further improvement in related technologies. Summary of the Invention

[0004] This application provides a battery device and an electrical device that can release the internal pressure of a single soft-pack battery cell, slow down the rate of heat spread, improve the reliability of the battery device, and at the same time, can take into account the energy density of the battery device to a certain extent.

[0005] In a first aspect, embodiments of this application provide a battery device, comprising: a housing having a receiving cavity and a discharging cavity, the discharging cavity being disposed around the outer periphery of the receiving cavity and communicating with the receiving cavity through a connecting hole; and a battery pack disposed within the receiving cavity, comprising a housing and a plurality of pouch battery cells housed in the housing, the housing having a weak portion configured to release internal pressure of the pouch battery cells.

[0006] In the above technical solution, by setting up a receiving cavity that is connected to the discharge cavity through a connecting hole, the discharge material will be discharged into the discharge cavity when the soft-pack battery cell is depressurized, thereby relieving the internal pressure of the soft-pack battery cell. Of course, it can also release the temperature of the soft-pack battery cell to a certain extent. Moreover, the discharge material entering the discharge cavity can be separated from the soft-pack battery cell in the receiving cavity to a certain extent, which helps to slow down the rate of heat spread of the battery device and improve the reliability of the battery device. In addition, the discharge cavity does not occupy the arrangement space provided by the receiving cavity for the soft-pack battery cell, which makes it easier for the battery device to have good energy density, and the layout is simple and easy to implement.

[0007] In some embodiments, the housing has a U-shaped mounting cavity with a first open side and a closed side disposed 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 disposed opposite to each other, and the second open side and the third open side are respectively provided with weak portions, and the tabs of the pouch battery cells extend out of the housing from the corresponding weak portions.

[0008] In the above technical solution, for the structure where the shell defines the U-shaped mounting cavity, the location of the weak point is relatively flexible. A suitable location can be selected according to different needs to better meet practical applications. Furthermore, a suitable weak structure can be selected based on the location of the weak point to ensure a good match between the weak structure and its location. It can be understood that when the second and third open sides are respectively provided with weak points, the weak points can be formed as clearance openings or open openings, which simplifies the structure of the weak points and facilitates 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 reduction section. The above technical solutions provide more options for the design of the weak portion to meet different usage requirements.

[0010] In some embodiments, if the volumetric energy density ρ of a single pouch battery cell is ≥390Wh / L, then the opening area S of the connecting hole is ≥100cm². 2 If the number of connecting holes n≥8; and the volumetric energy density ρ of a single soft-pack battery cell is <390Wh / L, then the opening area of ​​the connecting holes is 100cm². 2 >S≥55cm 2 The number of connecting holes is 8 > n ≥ 4.

[0011] In the above technical solution, the opening area and number of the connecting holes can be set according to the volumetric energy density of the soft-pack battery cell, so that the opening area and number of the connecting holes are well matched with the volumetric energy density of the soft-pack battery cell. This can ensure that the opening of the connecting holes meets the pressure relief requirements of the soft-pack battery cell, while also taking into account the structural strength of the casing and avoiding excessive weakening of the casing.

[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 and spaced apart from the connecting hole, and the high temperature resistance of the first protective member being superior to the high temperature resistance of the housing.

[0013] In the above technical solution, the setting of the first protective component will not affect the connection between the receiving cavity and the discharge cavity through the connecting hole, thus it will not affect the pressure relief of the soft-pack battery cell. Moreover, since the first protective component is opposite to the connecting hole and has good high temperature resistance, at least part of the discharge material discharged from the receiving cavity to the discharge cavity through the connecting hole will directly hit the first protective component. The first protective component can separate the discharge material (such as the high temperature and high pressure airflow generated inside the soft-pack battery cell when the soft-pack battery cell fails thermally, or even the airflow with sparks and electrolyte, etc.) from the inner wall of the discharge cavity to play a protective role, reduce the damage to the box body caused by the jet impact of high temperature and high pressure discharge material, and help improve the structural stability and reliability of the box body.

[0014] In some embodiments, there are multiple connecting holes spaced apart along the circumferential direction of the discharge chamber, 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 to adapt to the situation of thermal runaway of the pouch battery cells at different locations. It is beneficial to ensure that at least one of the multiple connecting holes has a discharge path of appropriate length corresponding to the thermal runaway pouch battery cell, which is convenient to balance discharge smoothness and discharge resistance. At the same time, since each connecting hole corresponds to a first protective member, no matter which connecting hole the discharge material enters the discharge chamber from, the corresponding first protective member can protect the casing, thereby improving the reliability of the casing.

[0015] In some embodiments, on a preset plane, the orthographic projection of the wall of the connecting hole lies within the orthographic projection range of the first protective member, and the preset plane is perpendicular to the axis of the connecting 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 connecting hole, which can increase the protective area of ​​the first protective member. This makes it easier for at least most of the emissions ejected from the connecting hole to directly hit the first protective member and not hit the inner wall of the emission chamber, thereby improving the protective effect of the first protective member on the housing and further reducing the impact of emissions on the housing.

[0016] In some embodiments, on a preset plane, the minimum distance x between the orthographic projection of the 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 distance x between the orthographic projection of the wall of the connecting hole and the outer contour of the orthographic projection of the first protective member on the preset plane to ≥ 5mm, the difference between the covering area of ​​the first protective member and the opening area of ​​the connecting hole is further increased, thereby further increasing the protective area of ​​the first protective member. This facilitates that all emissions ejected from the connecting hole directly impact the first protective member and do not impact the inner wall of the emission chamber, thus improving the protective effect on the housing.

[0017] In some embodiments, the first protective member is integrated into the housing; or, the first protective member is fixed to the inner wall of the discharge chamber. In the above technical solutions, the arrangement of the first protective member is flexible, facilitating the configuration of the connection between the first protective member and the housing according to different needs, thus better meeting actual requirements.

[0018] In some embodiments, the first protective member includes multiple protective layers arranged sequentially along the axial direction of the connecting hole. These layers are made of different materials, and in adjacent protective layers, the protective layer adjacent to the connecting hole exhibits better high-temperature resistance than the protective layer farther from the connecting hole. In the above technical solution, 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. Therefore, in the above solution, setting the high-temperature resistance of the protective layer adjacent to the connecting hole to be better than that of the protective layer farther from the connecting hole allows for a reasonable reduction in the high-temperature resistance requirement of the protective layer farther from the connecting hole while ensuring reliable resistance to the high-temperature jet impact of the emission. This is beneficial for reducing the material cost of the first protective member.

[0019] In some embodiments, the first protective component is a ceramic composite material, a mica component, a fiberglass component, or a coating disposed on the inner wall of the discharge chamber. In the above technical solutions, these materials possess excellent high-temperature resistance, enabling them to withstand the impact of emissions ejected from the connecting holes when the pouch battery cell releases internal pressure. Simultaneously, these materials have good processing properties, facilitating reliable placement within the discharge chamber.

[0020] In some embodiments, the first protective member is formed as a sheet structure, and the thickness of the first protective member is t, where 0.3mm≤t≤3mm. In the above technical solution, by setting the first protective member as a sheet structure, the structure of the first protective member is simplified and the processing is convenient. At the same time, the first protective member has a reasonable thickness, which makes it easy to balance its own reliability and the protective effect on the housing, and does not occupy too much space in the discharge chamber.

[0021] In some embodiments, the housing has weak points at both ends in the first horizontal direction, and a storage groove is formed at the bottom of the housing corresponding to the end where the weak point is located. The bottom wall of the storage groove is lower than that of the pouch battery cell. In the above technical solution, when the pouch battery cell experiences thermal runaway, the liquid, particles, etc. in the emissions can be intercepted by the weak points, and the intercepted liquid, particles, etc. flow downwards into the storage groove for storage. This can separate the emissions intercepted in the housing from the pouch battery cell, making it less likely for these emissions to come into contact with the pouch battery cell and puncture the packaging of the pouch battery cell, causing insulation failure of the pouch battery cell, etc., which is beneficial to improving the insulation reliability of the battery device during thermal runaway pressure relief.

[0022] In some embodiments, the individual pouch battery cells are positioned above the opening of the storage tank. By setting the individual pouch battery cells above the opening of the storage tank, the distance between the discharged material in the storage tank and the individual pouch battery cells is increased, further enhancing the storage tank's ability to separate the discharged material from the individual pouch battery cells. This reduces the probability of the discharged material coming into contact with the individual pouch battery cells, and further improves the insulation reliability of the battery device during thermal runaway pressure relief.

[0023] In some embodiments, the bottom of the housing has an opening, and a supporting protrusion protrudes from the bottom of the receiving cavity. The supporting protrusion supports and is bonded to the pouch battery cell. The housing forms a downward-facing receiving groove between two storage slots, with the opening formed on the top wall of the receiving groove. At least a portion of the supporting protrusion is received in the receiving groove and abuts against the groove wall. In the above technical solution, by providing the supporting protrusion and the receiving groove, the groove wall of the storage groove can cooperate with the supporting protrusion to achieve the supporting effect of the supporting protrusion on 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 housing. Combined with the setting of the supporting protrusion, it is beneficial to improve the structural stability of the opening and the installation stability of the battery pack.

[0024] In some embodiments, the battery device further includes a pressure relief structure, disposed on one side of the housing in the second horizontal direction, or on the bottom side of the housing. The pressure relief structure is correspondingly connected to the discharge chamber, and the pressure relief structure and the connecting hole are spaced apart along the circumferential direction of the discharge chamber. In the above technical solution, by providing a pressure relief structure correspondingly connected to the discharge chamber, the internal pressure of the discharge chamber can be released, so that the emissions emitted during thermal runaway of the pouch battery cell can be discharged out of the battery device through the pressure relief structure, which helps to slow down the rate of heat spread. Moreover, the pressure relief structure and the connecting hole are spaced apart along the circumferential direction of the discharge chamber, so that the emissions at the connecting hole need to flow through a certain path after flowing into the discharge chamber before flowing to the pressure relief structure, so as to achieve smooth discharge, while taking into account a certain exhaust resistance, and improving the problem that the discharge is prone to ignition due to excessively smooth discharge.

[0025] In some embodiments, the distance y between the pressure relief structure and the connecting hole in the direction surrounding the discharge chamber is ≥10cm. In the above technical solution, by setting the distance y between the pressure relief structure and the connecting hole in the direction surrounding the discharge chamber to ≥10cm, the discharge material at the connecting hole must flow through a path of at least 10cm in length after flowing into the discharge chamber before flowing to the pressure relief structure, so as to achieve smooth discharge, while taking into account a certain amount of exhaust resistance, which is beneficial to further improve the problem of easy ignition due to excessively smooth discharge.

[0026] In some embodiments, the discharge chamber includes a first discharge section and a second discharge section that are bent and connected. The second discharge section is connected to a connecting hole through the first discharge section, and a pressure relief structure is disposed on the second discharge section. In the above technical solution, with the connecting hole on the first discharge section and the pressure relief structure on the second discharge section, and the first and second discharge sections being bent and connected, the discharge material at the connecting hole needs to flow through a certain path after entering the discharge chamber before flowing to the pressure relief structure. Furthermore, the discharge material at the connecting hole needs to turn after entering the discharge chamber before flowing to the pressure relief structure. This ensures smooth discharge while also taking into account a certain amount of exhaust resistance, thus mitigating the problem of easy ignition due to excessively smooth discharge.

[0027] In some embodiments, when the volumetric energy density ρ of the pouch cell is ≥ 390 Wh / L, the number of pressure relief structures is multiple; when the volumetric energy density ρ of the pouch cell is < 390 Wh / 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 volumetric energy density of the pouch cell, so that the number of pressure relief structures and the volumetric energy density of the pouch cell are well matched. This ensures that the opening of the connecting hole meets the pressure relief requirements of the pouch cell, while also maintaining the structural strength of the casing and preventing excessive weakening of the casing.

[0028] In some embodiments, the housing includes a top plate, a bottom plate, and a frame. The frame surrounds the bottom plate and, together with the bottom plate and the top plate, defines a receiving cavity. A discharge cavity is formed within the frame, and a connecting hole is formed on the inner peripheral wall of the frame. In the above technical solution, by configuring the housing to include a top plate, a bottom plate, and a frame, and such that the frame, the top plate, and the bottom plate define a receiving cavity, while the discharge cavity is formed within the frame, the processing and shaping of the receiving cavity and the discharge cavity are facilitated, making it easier to arrange the discharge cavity around the receiving cavity, and also facilitating the assembly of the housing. It is understood that the connection method between the frame and the top plate, and the connection method between the frame and the bottom plate, are not specifically limited in this application.

[0029] In some embodiments, the frame includes a plurality of side beams connected end to end, at least a portion of which is hollow to define the discharge cavity. In the above technical solution, by providing a frame with multiple side beams that help define the discharge cavity, the frame structure is simplified, the discharge cavity is easily shaped, and the arrangement of multiple side beams allows for flexible setting of the surrounding length of the discharge cavity.

[0030] In some embodiments, the discharge chamber includes a bent and connected first discharge section and a second discharge section. The plurality of side beams include two first side beams arranged opposite each other along a first horizontal direction and two second side beams arranged opposite 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 has a plurality of connecting holes. In the above technical solution, the first and second discharge sections are bent and connected, and the second discharge section can connect with the connecting holes through the first discharge section. This facilitates the application of appropriate discharge resistance while ensuring smooth discharge of pollutants, thus mitigating the problem of easy ignition due to excessively smooth discharge. Furthermore, the frame structure is simple and easy to manufacture.

[0031] In some embodiments, the top of the housing is provided with a pressure relief structure, and the battery device further includes a second protective member disposed between the top plate and the battery pack to separate the pressure relief structure from the top plate.

[0032] In the above technical solution, the setting of the second protective component will not affect the normal pressure relief release of the pressure relief structure. Moreover, at least part of the emissions emitted toward the pressure relief structure will directly hit the second protective component. The second protective component 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 jet impact of high temperature and high pressure emissions, and help improve the reliability of pressure relief and the reliability of battery device use.

[0033] In some embodiments, the battery pack is multiple packs, and the battery device further includes at least one of a first heat exchanger and a second heat exchanger. At least one of the first heat exchanger and the second heat exchanger is used for heat exchange with the individual pouch battery cells. The first heat exchanger is disposed between two adjacent battery packs, and the second heat exchanger is disposed between the battery pack and the housing.

[0034] In some embodiments, the pouch cell is any one of a lithium iron phosphate battery cell, a ternary lithium battery cell, and a solid-state battery cell. The use of these types of pouch cells in the above technical solutions provides more options for battery device design to meet different application requirements. Specifically, a lithium iron phosphate battery cell offers advantages such as high reliability, long cycle life, light weight, large capacity, and low internal resistance; a ternary lithium battery cell offers advantages such as high energy density and good electrochemical performance; and a solid-state battery cell offers advantages such as high energy density, high reliability, light weight, and good high and low temperature performance.

[0035] In some embodiments, the soft-pack battery cell is a lithium iron phosphate battery cell, and the ratio of the amount of positive active material, binder and conductive agent in the positive electrode material of the soft-pack battery cell is 96:(1-3):(1-3); the soft-pack battery cell is a ternary battery cell, and the ratio of the amount of the amount of positive active material, binder and conductive agent in the positive electrode material of the soft-pack battery cell is 96:(2-3):(1-2).

[0036] In the above technical solutions, when the pouch battery cell is a lithium iron phosphate battery cell, a high proportion of positive electrode active material means that more substances capable of electrochemical reactions can be accommodated within a limited electrode assembly. This is beneficial for increasing the capacity and energy density of the battery device, allowing the lithium iron phosphate battery cell to output higher power while maintaining a relatively small volume and weight, meeting the application scenarios with certain energy density requirements. Using the above-mentioned range for binder and conductive agent dosages can reduce the cost of auxiliary materials, thereby reducing the overall cost of the battery device. When the pouch battery cell is a ternary lithium battery cell, due to the relatively complex structure and surface properties of ternary materials, using the above-mentioned proportions of positive electrode active material, binder, and conductive agent helps ensure good adhesion between positive electrode active material particles and between the active material and the current collector, thereby improving the mechanical stability and integrity of the electrode assembly. This helps reduce the risk of active material detachment and electrode pulverization during charging and discharging, extending the cycle life of the battery device.

[0037] Secondly, embodiments of this application provide an electrical device, including the battery device described above.

[0038] In the above technical solution, since the battery device has high reliability, using the battery device can improve the power reliability of the power-consuming device. Attached Figure Description

[0039] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0040] Figure 1 is a schematic diagram of the structure of an electrical device provided in some embodiments of this application as a vehicle;

[0041] Figure 2 is an exploded view of the structure of a battery device provided in some embodiments of this application;

[0042] Figure 3 is an exploded view of the structure of a battery device provided in another embodiment of this application;

[0043] Figure 4 is a schematic diagram of the battery pack shown in Figure 3;

[0044] Figure 5 is a schematic diagram of a battery device provided in some embodiments of this application;

[0045] Figure 6 is another schematic diagram of the battery device shown in Figure 5;

[0046] Figure 7 is a schematic diagram of a battery device provided in some embodiments of this application;

[0047] Figure 8 shows the results of pressure relief tests on three different examples of battery devices.

[0048] Figure 9 shows the results of pressure relief tests on three different examples of battery devices.

[0049] Figure 10 shows the results of pressure relief tests on three different examples of battery devices.

[0050] Reference numerals: Electrical device 1000, Battery device 100, Controller 200, Motor 300 Box 1, receiving cavity 1a, discharge cavity 1b, connecting 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 part 210, U-shaped mounting cavity 21a, first open side 21b, closed side 21c, second open side 21d, third open side 21e, opening 21f, storage slot 21g, receiving slot 21h, first shell wall 211, second shell wall 212, third shell wall 213, first shell part 214, second shell part 215, third shell part 216, flange part 217, soft pack battery cell 22, first protective component 3, pressure relief structure 4. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0053] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0054] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0055] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0056] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of the various components shown in the accompanying drawings in the embodiments of this application are merely illustrative and should not constitute any limitation on this application. The term "multiple" in this application refers to two or more (including two).

[0057] In this application, the battery cell 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-acid batteries, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, and the embodiments of this application are not limited thereto.

[0058] The battery apparatus mentioned in the embodiments of this application can refer to an assembly of one or more battery cells for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar. In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0059] As an example, a battery cell assembly can be a battery module, which consists of multiple battery cells arranged and fixed together to form a single module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0060] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing. As an example, the individual battery cell assembly may be a battery pack, which can be housed within the housing by securing the battery pack to the housing. Alternatively, the individual battery cell assembly may be housed within the housing by directly securing multiple individual battery cells to the housing. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0061] A battery cell includes a casing, electrode assembly, and electrolyte. The casing houses the electrode assembly and electrolyte. In this application, the battery cell can be a pouch cell, which refers to a battery cell using a flexible outer packaging material as its casing. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrode. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated positive current collector, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the negative current collector without the negative active material layer protrudes from the one with the negative active material layer. The negative current collector without the negative active material layer serves as the negative electrode tab. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc. To ensure that a large current can be passed without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together.

[0062] The separator can be made of PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these.

[0063] In recent years, new energy vehicles have experienced rapid development, and battery devices, as the power source of electric vehicles, play an irreplaceable and crucial role. Among these, battery devices utilize individual battery cells to store and provide electrical energy, and among the many types of battery cells, pouch cells have been widely used due to their unique structure and advantages.

[0064] In related technologies, in general battery devices, multiple pouch cell batteries are usually installed side by side during production and assembly. When a pouch cell battery experiences thermal runaway, it is difficult to depressurize the cell in a timely manner, which makes the battery device prone to rapid thermal propagation and makes it difficult to maintain the energy density of the battery device.

[0065] Based on the above considerations, a battery device is proposed, which includes a housing and a battery pack. The housing has a receiving cavity and a discharging cavity. The discharging cavity is arranged around the outer periphery of the receiving cavity and communicates with the receiving cavity through a connecting hole. The battery pack is disposed in the receiving cavity and includes a housing and a plurality of pouch battery cells housed in the housing. The housing has a weak portion, which is configured to release the internal pressure of the pouch battery cells.

[0066] In the above technical solution, by setting up a receiving cavity that is connected to the discharge cavity through a connecting hole, the discharge material will be discharged into the discharge cavity when the soft-pack battery cell is depressurized, thereby relieving the internal pressure of the soft-pack battery cell. Of course, it can also release the temperature of the soft-pack battery cell to a certain extent. Moreover, the discharge material entering the discharge cavity can be separated from the soft-pack battery cell in the receiving cavity to a certain extent, which helps to slow down the rate of heat spread of the battery device and improve the reliability of the battery device. In addition, the discharge cavity does not occupy the arrangement space provided by the receiving cavity for the soft-pack battery cell, which makes it easier for the battery device to have good energy density, and the layout is simple and easy to implement.

[0067] The battery device disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system incorporating the battery device disclosed in this application can be used to construct such an electrical device.

[0068] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0069] For ease of explanation, the following embodiments use a vehicle as an example of an electrical device 1000 according to one embodiment of this application. Please refer to Figure 1, which is a structural schematic diagram of a vehicle provided in some embodiments of this application for the electrical device 1000. The vehicle can be a gasoline vehicle, a natural gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery device 100 is provided inside the vehicle, and the battery device 100 can be located at the bottom, front, or rear of the vehicle. The battery device 100 can be used to power the vehicle; for example, the battery device 100 can serve as the vehicle's operating power source. The vehicle may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle during starting, navigation, and driving.

[0070] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0071] Please refer to Figure 2, which is an exploded view of the structure of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 and a plurality of battery cells 20, which are housed within the housing 10. The housing 10 provides assembly space for the battery cells 20, and the housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which cover each other, and the first housing body 11 and the second housing body 12 together define an assembly space for accommodating the battery cells 20. The second housing body 12 may be a hollow structure open at one end, and the first housing body 11 may be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12 so that the first housing body 11 and the second housing body 12 together define the assembly space; the first housing body 11 and the second housing body 12 may also be hollow structures both open on one side, with the open side of the first housing body 11 covering the open side of the second housing body 12. Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as cylinder, cuboid, etc.

[0072] In the battery device 100, multiple battery cells 20 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0073] Please refer to Figure 2, which is an exploded view of the structure of a battery device 100 provided in some embodiments of this application. The battery device 100 includes multiple rows of battery cells 20, which are arranged along the length of the housing 10. Each row of battery cells 20 includes multiple battery cells 20 arranged along the width of the housing 10; or, the multiple rows of battery cells 20 are arranged along the width of the housing 10, and each row of battery cells 20 includes multiple battery cells 20 arranged along the length of the housing 10.

[0074] Each battery cell 20 can be a secondary battery or a primary battery. A secondary battery refers to a battery cell 20 that can be recharged after discharge to activate the active materials and continue to be used. It can also be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment is not limited in this regard. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes. For example, in Figure 2, the battery cell 20 is cuboid.

[0075] For example, as shown in Figure 3, the battery cell 20 is generally rectangular, with its height direction being the third direction Z, its length direction being the second direction Y, and its thickness direction being the first direction X. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other. However, this is not a limitation; in other embodiments of this application, the battery cell 20 may also be a polygonal prism, a flat body, or other shapes.

[0076] Referring to Figures 3 and 5, in the embodiments of this application, the battery device 100 includes a housing 1 and a battery pack 2.

[0077] The housing 1 has a receiving cavity 1a and a discharging cavity 1b. The battery pack 2 is disposed within the receiving cavity 1a, and the discharging cavity 1b is disposed around the outer periphery of the receiving cavity 1a and communicates with the receiving cavity 1a through a connecting hole 1c. The battery pack 2 includes a housing 21 and a plurality of pouch battery cells 22 housed in the housing 21. The housing 21 has a weak portion 210, which is configured to release the internal pressure of the pouch battery cells 22. Exemplarily, the plurality of pouch battery cells 22 of the battery pack 2 can be arranged sequentially along a first direction.

[0078] As can be seen, the design of the weak point 210 can achieve pressure relief of the pouch battery cell 22. For example, the weak point 210 is the weakest point on the casing 21. When the pressure inside the pouch battery cell 22 reaches a threshold, the pressure on the weak point 210 reaches its maximum capacity, causing the weak point 210 to be broken through by the internal pressure of the pouch battery cell 22. A channel connecting the inside and outside of the pouch battery cell 22 is formed at the corresponding position of the weak point 210. The channel can release the internal pressure of the pouch battery cell 22. The above threshold design varies depending on the design requirements.

[0079] When the soft-pack battery cell 22 is depressurized, the discharge will be discharged into the receiving cavity 1a. The receiving cavity 1a is connected to the discharge cavity 1b through the connecting hole 1c. The discharge can flow into the discharge cavity 1b through the connecting hole to release the pressure inside the soft-pack battery cell 22. It can also release the temperature of the soft-pack battery cell 22 to a certain extent. In addition, the discharge entering the discharge cavity 1b can be separated from the soft-pack battery cell 22 in the receiving cavity 1a to a certain extent, which helps to slow down the rate of heat spread of the battery device 100.

[0080] Furthermore, since the discharge chamber 1b is arranged around the outer periphery of the receiving chamber 1a, the discharge chamber 1b will not occupy the internal space of the receiving chamber 1a, nor will it occupy the arrangement space provided by the receiving chamber 1a for the soft-pack battery cell 22. This facilitates the battery device 100 to have good energy density. Moreover, the above arrangement of the discharge chamber 1b and the receiving chamber 1a makes their relative positions relatively simple, which is convenient for the processing of the housing 1. In addition, 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 of the discharge material to a certain extent, so as to select a suitable location to discharge the discharge material.

[0081] Of course, the enclosure 1 defines the discharge chamber 1b, which not only allows the discharge of the soft-pack battery cell 22 when it is depressurized, but also makes the part of the enclosure 1 corresponding to the discharge chamber 1b a hollow structure. This reduces the amount of material used in the enclosure 1 and lowers its weight while maintaining the structural strength of the enclosure 1, which is beneficial to improving the energy density of the battery device 100 to a certain extent.

[0082] For example, the discharge cavity 1b is disposed around the outer periphery of the receiving cavity 1a. The outer periphery of the receiving cavity 1a may include multiple sides. The discharge cavity 1b may be disposed on one of the multiple sides of the receiving cavity 1a, or the discharge cavity 1b may be disposed on at least two of the multiple sides of the receiving cavity 1a. The discharge cavity 1b may extend along a straight line or along a curve. For example, the discharge cavity 1b may extend into a closed ring (as shown in Figure 5) or an open ring. For example, the discharge cavity 1b may extend into an L-shape, U-shape, or C-shape. "Open ring" refers to a ring with an opening, i.e., a non-closed ring. "Ring" is interpreted in a broad sense, i.e., not limited to "circular ring". For example, it may also be a "polygonal ring", etc.

[0083] Please refer to Figures 3 and 4. In some embodiments, the housing 21 has a U-shaped mounting cavity 21a, which has a first open side 21b and a closed side 21c arranged opposite to each other. The closed side 21c is provided with a weak portion 210. And / or, the housing 21 has a U-shaped mounting cavity 21a, which has a second open side 21d and a third open side 21e arranged opposite to each other. 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 extend out of the housing 21 from the corresponding weak portions 210.

[0084] It is evident that, for the structure of the housing 21 defining the U-shaped mounting cavity 21a, the location of the weak portion 210 is quite flexible. A suitable location can be selected according to different needs to better meet practical applications. Furthermore, a suitable weak structure can be selected based on the different locations of the weak portion 210 to ensure a good match between the weak structure and its location. It can be understood that when the second open side 21d and the third open side 21e are respectively provided with weak portions 210, the weak portion 210 can be formed as a clearance opening or an opening 21f, which simplifies the structure of the weak portion 210 and facilitates processing.

[0085] For example, the weak part 210 is provided on the closed side 21c, and the weak part 210 can be a groove or a weakening part; the weak part 210 is provided on the second open side 21d and the third open side 21e, and the weak part 210 can be a pressure relief hole.

[0086] In the example of Figure 4, the housing 21 includes a first housing wall 211, a second housing wall 212, and a third housing wall 213. The first housing wall 211 and the third housing wall 213 are arranged opposite each other along the width direction of the housing 21. The second housing wall 212 is bent and connected between the first housing wall 211 and the third housing wall 213, so that the first housing wall 211, the second housing wall 212, and the third housing wall 213 define a U-shaped mounting cavity 21a. The second housing wall 212 is connected to one end of the first housing wall 211 and the third housing wall 213 in the height direction of the housing 21. Then, the second housing wall 212 corresponds to the closed side 21c, the opening 21f of the housing 21 opposite to the second housing 21 corresponds to the first open side 21b, and the two sides in the length direction of the housing 21 correspond to the second open side 21d and the third open side 21e, respectively. The width direction of the housing 21 can be a first direction, the height direction of the housing 21 can be a third direction, and the length direction of the housing 21 can be a second direction.

[0087] Of course, in other embodiments, the U-shaped mounting cavity 21a may not have a second open side 21d and a third open side 21e. In this case, the housing 21 is closed on both sides corresponding to the second open side 21d and the third open side 21e, for example, by the first housing portion 214 described later.

[0088] In some embodiments, the weak portion 210 is configured as a pressure relief hole; or, the weak portion 210 is configured as a groove; or, the weak portion 210 is configured as a weakening portion. The above technical solutions provide more options for the specific structural design of the weak portion 210 to meet different usage requirements.

[0089] In some embodiments, if the volumetric energy density ρ of the pouch cell 22 is ≥390Wh / L, then the opening area S of the connecting hole 1c is ≥100cm². 2 If the number of connecting holes 1c is n≥8; and the volumetric energy density ρ of the soft-pack battery cell 22 is <390Wh / L, then the opening area of ​​connecting hole 1c is 100cm². 2 >S≥55cm 2 The number of connecting holes 1c is 8 > n ≥ 4.

[0090] When the volumetric energy density ρ of the pouch cell 22 is greater than or equal to 390Wh / L, the energy released and heat generated when the pouch cell 22 experiences thermal runaway are relatively large, and the opening area S of the connecting hole 1c is ≥100cm². 2The number of openings n≥8, so that the emissions from the pouch cell 22 can be discharged in a timely manner through the connecting hole 1c, which helps to reduce the impact on other pouch cells 22 that have not yet experienced thermal runaway and slows down heat propagation; when the energy density ρ of the pouch cell 22 is less than 390Wh / L, the energy released and the heat generated when the pouch cell 22 experiences thermal runaway are relatively small, and the opening area of ​​the connecting hole 1c is 100cm². 2 >S≥55cm 2 The number of openings is 8 > n ≥ 4, so that the emissions from the soft-pack battery cells 22 can be discharged in time through the connecting hole 1c, while also helping to reduce the weakening of the casing 1.

[0091] As can be seen, in the above technical solution, the opening area and number of openings of the connecting hole 1c can be set according to the volumetric energy density of the soft-pack battery cell 22, so that the opening area and number of openings of the connecting hole 1c are well matched with the volumetric energy density of the soft-pack battery cell 22. This can ensure that the opening of the connecting hole 1c meets the pressure relief requirements of the soft-pack battery cell 22, while also taking into account the structural strength of the housing 1, and is not likely to cause excessive weakening of the housing 1.

[0092] Optionally, in the above scheme, the multiple connecting holes 1c can be spaced apart along the extension direction of the discharge cavity 1b.

[0093] For example, as shown in Figure 8, pressure relief tests were conducted on three different examples. All three examples had the same number of connecting holes 1c, and the energy density ρ of the pouch cell 22 was also the same, at 380Wh / L. The difference between the three was the opening area of ​​the connecting holes 1c; in Example 1, the opening area of ​​the connecting hole 1c was 40cm². 2 In Example 2, the opening area of ​​the connecting hole 1c is 60 cm². 2 In Example 3, the opening area of ​​the connecting hole 1c is 80 cm². 2 As shown in Figure 8, in Example 1, the peak internal pressure of the battery device 100 exceeded 20 kPa during the entire depressurization process, while the peak internal pressures in Examples 2 and 3 did not exceed 20 kPa. Compared to Example 1, the battery device 100 is less prone to significant bulging and deformation, and is less likely to experience airtightness problems due to the large peak internal pressure during depressurization. Therefore, Examples 2 and 3 are superior to Example 1. It can be understood that if the peak internal pressure of the battery device 100 exceeds 20 kPa during the depressurization test, it indicates that the battery device 100 is prone to significant bulging and deformation, and is likely to experience airtightness problems subsequently.

[0094] As shown in Figure 9, pressure relief tests were conducted on three different examples. All three examples had the same number of connecting holes 1c, and the opening area of ​​each connecting hole 1c was also the same, 60 cm². 2The difference among the three lies in the energy density ρ of the pouch cell 22. In Example 4, the energy density ρ of the pouch cell 22 is 420Wh / L, in Example 5 it is 390Wh / L, and in Example 6 it is 360Wh / L. As can be seen from Figure 9, in Example 4, the peak internal pressure of the battery device 100 exceeds 20kPa during the entire depressurization process, while the peak internal pressure of Example 5 and Example 6 does not exceed 20kPa. Compared with Example 4, the battery device 100 is less prone to large bulging and deformation, and is less likely to have airtightness problems due to the large peak internal pressure during the depressurization process. That is, Example 5 and Example 6 are better than Example 4.

[0095] As shown in Figure 10, pressure relief tests were conducted on three different examples. All three examples had the same number of connecting holes 1c, and the energy density ρ of the pouch cell 22 was also the same, at 450 Wh / L. The difference between the three examples lay in the opening area of ​​the connecting holes 1c; in example 7, the opening area of ​​the connecting hole 1c was 70 cm². 2 In Example 8, the opening area of ​​the connecting hole 1c is 100 cm². 2 In Example 9, the opening area of ​​the connecting hole 1c is 130 cm². 2 As can be seen from Figure 10, in Example 7, the peak internal pressure of the battery device 100 exceeded 20 kPa during the entire depressurization process, while the peak internal pressure of Example 8 and Example 9 did not exceed 20 kPa. Compared with Example 7, the battery device 100 is less prone to large bulging and deformation, and is less likely to have airtightness problems due to the large peak internal pressure during the depressurization process. That is, Example 8 and Example 9 are better than Example 7.

[0096] Please refer to Figure 5. In some embodiments, the battery device 100 further includes a first protective member 3. The first protective member 3 is disposed in the discharge chamber 1b. The first protective member 3 is opposite to the connecting hole 1c and the first protective member 3 is spaced apart from the connecting hole 1c. The high temperature resistance of the first protective member 3 is better than that of the housing 1.

[0097] It is evident that the installation of the first protective component 3 will not affect the connection between the receiving cavity 1a and the discharge cavity 1b through the connecting hole 1c, thus not affecting the pressure relief of the soft-pack battery cell 22. Moreover, since the first protective component 3 is opposite to the connecting hole 1c and has good high-temperature resistance, at least a portion of the emissions discharged from the receiving cavity 1a through the connecting hole 1c toward the discharge cavity 1b will directly impact the first protective component 3. The first protective component 3 can separate the emissions, such as the high-temperature and high-pressure airflow generated inside the soft-pack battery cell 22 when it fails thermally, and even the airflow with sparks and electrolyte, from the inner wall of the discharge cavity 1b to provide protection. This reduces the risk of damage to the housing 1 due to the jet impact of high-temperature and high-pressure emissions, and helps to improve the structural stability and reliability of the housing 1.

[0098] It is understandable that the first protective component 3 can be connected to the inner wall of the discharge chamber 1b.

[0099] Please refer to Figure 5. In some embodiments, there are multiple connecting holes 1c, which are spaced apart along the surrounding direction of the discharge cavity 1b. Each connecting hole 1c corresponds to a first protective member 3.

[0100] It is evident that the arrangement of the multiple connecting holes 1c is relatively dispersed, which facilitates adaptation to the thermal runaway of the pouch cell 22 at different locations. This allows at least one of the multiple connecting holes 1c to have a discharge path of appropriate length corresponding to the thermally runaway pouch cell 22, thus balancing discharge smoothness and discharge resistance. At the same time, since each connecting hole 1c corresponds to a first protective component 3, regardless of which connecting hole 1c the discharge material enters the discharge chamber 1b from, the corresponding first protective component 3 can protect the housing 1, thereby improving the reliability of the housing 1.

[0101] For example, as shown in FIG5, the discharge chamber 1b includes a first discharge section 1e and a second discharge section 1f that are bent and connected. 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, with the two first discharge sections 1e arranged opposite each other and the two second discharge sections 1f arranged opposite each other. Each first discharge section 1e is connected to the two second discharge sections 1f, so that the entire discharge chamber 1b forms a closed ring. Each first discharge section 1e has a plurality of connecting holes 1c that are spaced apart along its length direction, while no connecting holes 1c are provided on the second discharge section 1f.

[0102] Please refer to Figure 5. In some embodiments, on a preset plane, the orthographic projection of the 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 axis of the connecting hole 1c.

[0103] As can be seen, 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 protective area of ​​the first protective member 3. This makes it easier for at least most of the emissions ejected from the connecting hole 1c to directly hit the first protective member 3 instead of hitting the inner wall of the emission chamber 1b. This is beneficial to improving the protective effect of the first protective member 3 on the housing 1 and further reducing the impact of emissions on the housing 1.

[0104] It is understood that in the embodiments of this 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. In other words, on the 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 of the outer contour of the first protective member 3.

[0105] Please refer to Figure 5. In some embodiments, the minimum distance x between the orthographic projection of the wall of the connecting hole 1c and the outer contour of the orthographic projection of the first protective member 3 on the preset plane is ≥5mm.

[0106] In the above technical solution, by setting a minimum distance x≥5mm between the orthographic projection of the 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 is further increased, thereby further increasing the protective area of ​​the first protective member 3. This makes it easier for all the emissions ejected from the connecting hole 1c to directly hit the first protective member 3 instead of hitting the inner wall of the discharge chamber 1b, thus improving the protective effect on the housing 1.

[0107] In some embodiments, the first protective member 3 is integrated into the housing 1, for example, the first protective member 3 is integrally connected to the housing 1. In this 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 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.

[0108] In the above technical solution, the first protective component 3 is set in a flexible manner, which makes it easy to set the connection method between the first protective component 3 and the housing 1 according to different needs, so as to better meet the actual needs.

[0109] It is understood that when the first protective component 3 is fixed to the inner wall of the discharge chamber 1b, the connection method between the first protective component 3 and the housing 1 is not specifically limited. For example, the first protective component 3 can be bonded to the inner wall of the discharge chamber 1b.

[0110] In some embodiments, the first protective member 3 includes multiple protective layers arranged sequentially along the axial direction of the connecting hole 1c. The multiple protective layers are made of different materials, and among two adjacent protective layers, the protective layer adjacent to the connecting hole 1c has better high-temperature resistance than the protective layer far from the connecting hole 1c.

[0111] It is evident that, among the two adjacent protective layers, the protective layer adjacent to the connecting hole 1c is closer to the emission and will preferentially withstand the high-temperature jet impact of the emission. Therefore, in the above scheme, the high-temperature resistance performance of the protective layer adjacent to the connecting hole 1c is set to be better than that of the protective layer far from the connecting hole 1c. This is to appropriately reduce the high-temperature resistance requirement of the protective layer far from the connecting hole 1c while ensuring reliable resistance to the high-temperature jet impact of the emission, which is beneficial to appropriately reducing the material cost of the first protective component 3.

[0112] Of course, the first protective component 3 can also be constructed as a protective layer, which is simple in structure and easy to process.

[0113] In some embodiments, the first protective component 3 is a ceramic composite material component, such as a TC composite strip, a mica component, a glass fiber component, or a high-temperature resistant coating disposed on the inner wall of the discharge chamber 1b.

[0114] It is evident that these materials possess excellent high-temperature resistance, enabling them to withstand the impact of emissions ejected from the connecting hole 1c when the internal pressure of the pouch cell 22 is released. Furthermore, these materials have good processing properties, making them easy to reliably install in the emission chamber 1b.

[0115] Please refer to Figures 5 and 6. In some embodiments, the first protective member 3 is formed as a sheet structure, and the thickness of the first protective member 3 is t, where 0.3mm≤t≤3mm.

[0116] In the above technical solution, by setting the first protective component 3 as a sheet structure, it is easy to simplify the structure of the first protective component 3 and facilitate processing. At the same time, the first protective component 3 has a reasonable thickness, which is convenient to take into account both its own reliability and the protective effect on the housing 1, and will not occupy too much space in the discharge chamber 1b.

[0117] For example, the thickness t of the first protective component 3 is 0.3mm, 0.5mm, 0.8mm, 1mm, 1.5mm, 2.2mm, 2.7mm, or 3mm, etc.

[0118] Referring to Figure 7, in some embodiments, the housing 21 has weak portions 210 at both ends in the first horizontal direction, and a storage groove 21g is formed at the bottom of the housing 21 corresponding to the end where the weak portion 210 is located. Thus, the housing 21 has storage grooves 21g at both ends in the first horizontal direction, with the opening of the storage groove 21g facing upwards. The bottom wall of the storage groove 21g is lower than the soft-pack battery cell 22, meaning that in the vertical direction, the bottom wall of the storage groove 21g is located below the soft-pack battery cell 22. For example, the first horizontal direction can be a second direction.

[0119] Therefore, when the pouch battery cell 22 experiences thermal runaway, the liquid and particles in the emissions can be intercepted by the weak part 210, and the intercepted liquid and particles flow downward into the storage tank 21g for storage. This can separate the emissions intercepted in the casing 21 from the pouch battery cell 22, making it less likely for these emissions to come into contact with the pouch battery cell 22 and puncture its packaging, or cause insulation failure. This is beneficial to improving the insulation reliability of the battery device 100 during thermal runaway pressure relief.

[0120] For example, as shown in FIG7, 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; this application does not impose specific restrictions on the formation method of the storage slot 21g, for example, the end of the housing 21 in the first horizontal direction can be bent multiple times to define the storage slot 21g with the slot opening facing upward.

[0121] Optionally, the two ends of the housing 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 portion 210 at both ends of the housing 21 in the first horizontal direction is not limited to the direction in which the housing 21 is open.

[0122] Please refer to Figure 7. In some embodiments, the pouch cell 22 is higher than the opening of the storage slot 21g.

[0123] In the above technical solution, by setting the opening of the soft-pack battery cell 22 higher than that of the storage tank 21g, it is beneficial to increase the distance between the discharge in the storage tank 21g and the soft-pack battery cell 22, further improving the ability of the storage tank 21g to separate the discharge in it from the soft-pack battery cell 22, reducing the probability of the discharge in the storage tank 21g coming into contact with the soft-pack battery cell 22, and further improving the insulation reliability of the battery device 100 during thermal runaway pressure relief discharge.

[0124] Please refer to Figure 7. In some embodiments, the bottom of the housing 21 has an opening 21f, and the bottom of the receiving cavity 1a has a supporting protrusion 1d. The supporting protrusion 1d is supported on the soft-pack battery cell 22 and is glued to the soft-pack battery cell 22. The housing 21 has a receiving groove 21h with the groove opening facing downward between the two storage grooves 21g. The opening 21f is formed on the top wall of the receiving groove 21h. At least a portion of the supporting protrusion 1d is received in the receiving groove 21h, and the supporting protrusion 1d abuts against the groove wall of the receiving groove 21h.

[0125] For example, the housing 21 may include a first housing portion 214, a second housing portion 215, and a third housing portion 216 connected by bending in sequence. The second housing portion 215 may define the bottom wall of the storage groove 21g. The first housing portion 214 and the third housing portion 213 respectively define the side walls of the storage groove 21g. The third housing portion 216 is located on the side of the first housing portion 214 facing the soft-pack battery cell 22. The end of the third housing portion 216 away from the first housing portion 211 has a flange portion 217. The flange portion 217 participates in defining the top wall of the receiving groove 21h. The third housing portion 216 participates in defining the side wall of the receiving groove 21h. The receiving groove 21h is located between two flange portions 217 arranged opposite each other in the first horizontal direction. Each flange portion 217 is abutted against the top of the support protrusion 1d. Further, each third housing portion 213 abuts against the outer peripheral wall of the support protrusion 1d. It is evident that the support protrusion 1d helps to raise the height of the soft-pack battery cell 22, thereby increasing the distance between the opening of the storage slot 21g and the soft-pack battery cell 22 in the vertical direction.

[0126] Optionally, the adhesive joint between the support protrusion 1d and the soft-pack battery cell 22 can be provided at the opening 21f of the housing 21.

[0127] In the above technical solution, by setting the support protrusion 1d and the receiving groove 21h, the groove wall of the storage groove 21g can cooperate with the support protrusion 1d to realize the support effect of the support protrusion 1d on the groove wall of the storage groove 21g, which is conducive to improving the structural stability of the storage groove 21g. At the same time, the setting of the storage groove 21g is conducive to enhancing the structural strength of the bottom of the shell 21. Together with the setting of the support protrusion 1d, it is conducive to improving the structural stability of the opening 21f and improving the setting stability of the battery pack 2.

[0128] Referring 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 housing 1 in the second horizontal direction, or on the bottom side of the housing 1. The pressure relief structure 4 is connected to the discharge chamber 1b, and the pressure relief structure 4 and the connecting hole 1c are spaced apart along the surrounding direction of the discharge chamber 1b. For example, the first horizontal direction can be a first direction.

[0129] For example, 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 the 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 release of internal pressure or temperature; the threshold design varies depending on the design requirements.

[0130] In the above technical solution, by setting a pressure relief structure 4 corresponding to and connected to the discharge chamber 1b, the internal pressure of the discharge chamber 1b can be released, so that the emissions emitted by the soft-pack battery cell 22 during thermal runaway can be discharged from the battery device 100 through the pressure relief structure 4, which helps to slow down the rate of heat spread. Moreover, the pressure relief structure 4 and the connecting hole 1c are spaced apart along the surrounding direction of the discharge chamber 1b, so that the emissions at the connecting hole 1c need to flow through a certain path after flowing into the discharge chamber 1b before flowing to the pressure relief structure 4, so as to achieve smooth discharge, while taking into account a certain amount of exhaust resistance, and improving the problem of easy ignition due to excessively smooth discharge. In addition, the setting position of the pressure relief structure 4 has a certain degree of flexibility to better meet the actual differentiated needs.

[0131] In this embodiment of the application, the second horizontal direction is parallel to or intersects with the first horizontal direction.

[0132] Referring to Figure 5, in some embodiments, the distance y between the pressure relief structure 4 and the connecting hole 1c in the direction surrounding the discharge chamber 1b is ≥10cm. Alternatively, the discharge at the connecting hole 1c flows through a path at least 10cm long before reaching the pressure relief structure 4.

[0133] In the above technical solution, by setting the distance y between the pressure relief structure 4 and the connecting hole 1c in the direction surrounding the discharge chamber 1b to be ≥10cm, the discharge material at the connecting hole 1c needs to flow through a path of at least 10cm in length after flowing into the discharge chamber 1b before flowing to the pressure relief structure 4, so as to achieve smooth discharge, while taking into account a certain amount of exhaust resistance, which is conducive to further improving the problem of easy ignition due to excessively smooth discharge.

[0134] It is understandable that when there are multiple pressure relief structures 4, the distance between each pressure relief structure 4 and any connecting hole 1c in the direction surrounding the discharge chamber 1b is greater than or equal to 10cm.

[0135] Referring 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. 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 turn and flow to the second discharge section 1f, and be released through the pressure relief structure 4.

[0136] In the above technical solution, the connecting hole 1c is set on the first discharge section 1e, and the pressure relief structure 4 is set on the second discharge section 1f. The first discharge section 1e and the second discharge section 1f are connected by a bend. Then, the discharge at the connecting hole 1c needs to flow through a path after flowing into the discharge chamber 1b before flowing to the pressure relief structure 4. Moreover, the discharge at the connecting hole 1c needs to turn after flowing into the discharge chamber 1b before flowing to the pressure relief structure 4. In order to achieve smooth discharge, a certain amount of exhaust resistance can be taken into account, thereby improving the problem of easy ignition due to excessively smooth discharge.

[0137] In some embodiments, when the volumetric energy density ρ of the pouch cell 22 is ≥390Wh / L, the number of pressure relief structures 4 is multiple; when the volumetric energy density ρ of the pouch cell 22 is <390Wh / L, the number of pressure relief structures 4 is one.

[0138] When the volumetric energy density ρ of the pouch cell 22 is greater than or equal to 390Wh / L, the energy released and heat generated when the pouch cell 22 experiences thermal runaway are relatively large. Multiple pressure relief structures 4 can be used to 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 pouch cell 22 is less than 390Wh / L, the energy released and heat generated when the pouch cell 22 experiences thermal runaway are relatively small. Only one pressure relief structure 4 is used so that the emissions from the pouch cell 22 can be discharged in a timely manner through the pressure relief structure 4. At the same time, it is beneficial to reduce the number of pressure relief structures 4 and simplify the structure of the battery device 100.

[0139] As can be seen, in the above technical solution, the number of pressure relief structures 4 can be set according to the volumetric energy density of the soft-pack battery cell 22, so that the number of pressure relief structures 4 and the volumetric energy density of the soft-pack battery cell 22 are well matched. This can ensure that the opening of the connecting hole 1c meets the pressure relief requirements of the soft-pack battery cell 22, and also take into account the structural strength of the box 1, so as not to cause excessive weakening of the box 1.

[0140] Please refer to Figures 3-6. In some embodiments, the housing 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 receiving cavity 1a. A discharge cavity 1b is formed inside the frame 15, and a connecting hole 1c is formed on the inner peripheral wall of the frame 15.

[0141] It can be understood that the frame 15 is a closed ring structure. The inner peripheral wall of the frame 15 can help define the peripheral wall of the receiving cavity 1a and the peripheral wall of the discharge cavity 1b. Therefore, the inner peripheral wall of the frame 15 can separate the receiving cavity 1a and the discharge cavity 1b.

[0142] In the above technical solution, the housing 1 is constructed by including a top plate 13, a bottom plate 14, and a frame 15, such that the frame 15, the top plate 13, and the bottom plate 14 define a receiving cavity 1a, while a discharge cavity 1b is formed within the frame 15. This facilitates the processing and shaping of the receiving cavity 1a and the discharge cavity 1b, makes it easier for the discharge cavity 1b to be positioned around the receiving cavity 1a, and also facilitates the assembly of the housing 1. It is understood that the connection method between the frame 15 and the top plate 13, and the connection method between the frame 15 and the bottom plate 14, are not specifically limited in this application.

[0143] Please refer to Figures 3 and 5. In some embodiments, the frame 15 includes a plurality of side beams 151 connected end to end. At least a portion of the plurality of side beams 151 is hollow to define the discharge cavity 1b. At least one of the plurality of side beams 151 participates in defining the discharge cavity 1b.

[0144] In the above technical solution, by setting the frame 15 to include multiple side beams 151, the side beams 151 participate in defining the discharge cavity 1b, which simplifies the structure of the frame 15 and facilitates the processing and forming of the discharge cavity 1b. At the same time, the setting of multiple side beams 151 makes it convenient to flexibly set the surrounding length of the discharge cavity 1b.

[0145] For example, the frame 15 includes four side beams 151 connected end to end, each side beam 151 being hollow so that each side beam 151 participates in defining a portion of the discharge chamber 1b.

[0146] Please refer to Figure 5. In some embodiments, the discharge chamber 1b includes a bent and connected first discharge section 1e and a second discharge section 1f. The plurality of side beams 151 include two first side beams 1511 arranged opposite each other along a first horizontal direction and two second side beams 1512 arranged opposite each other 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 has a plurality of connecting holes 1c.

[0147] As can be seen, the first discharge section 1e and the second discharge section 1f are bent and connected, and the second discharge section 1f can be connected to the connecting hole 1c through the first discharge section 1e. This facilitates the application of appropriate discharge resistance while ensuring smooth discharge of the waste, thereby improving the problem of easy ignition due to excessively smooth discharge. Moreover, the frame 15 has a simple structure and is easy to process.

[0148] It is understood that the shape of the opening of the connecting hole 1c is not specifically limited in the embodiments of this application. For example, the connecting hole 1c can be a circular hole, a polygonal hole, an elliptical hole, etc.

[0149] In some embodiments, the top of the housing 21 is provided with a pressure relief structure 4, 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.

[0150] In the above technical solution, the installation of the second protective component does not affect the normal pressure relief of the pressure relief structure 4. Furthermore, at least a portion of the emissions directed towards the pressure relief structure 4 will directly impact the second protective component. This second protective component can separate the emissions from the pressure relief structure 4, providing protection and reducing the risk of damage to the pressure relief structure 4 due to the impact of high-temperature, high-pressure emissions. This improves pressure relief reliability and the overall reliability of the battery device 100. Additionally, if the battery device 100 is used in a vehicle and is located at the bottom of the vehicle, the second protective component can better isolate the emitted emissions from the occupants, improving driving performance.

[0151] In some embodiments, the battery pack 2 is multiple packs, and the battery device 100 further includes at least one of a first heat exchanger and a second heat exchanger, wherein the first heat exchanger and the second heat exchanger are used for heat exchange with the soft-pack battery cell 22; wherein the first heat exchanger is disposed between two adjacent battery packs 2, and the second heat exchanger is disposed between the battery pack 2 and the housing 1.

[0152] As can be seen, the first heat exchanger is located between two adjacent battery packs 2, for example, between the housings 21 of two adjacent battery packs 2. This allows the first heat exchanger to exchange heat with the two adjacent battery packs 2, so that the operating temperature of the multiple battery packs 2 can be maintained within a relatively suitable range. This helps to reduce the temperature difference between the battery packs 2 and improves the stability of the battery device 100. Moreover, by placing the first heat exchanger between two adjacent battery packs 2, the internal space of the battery device 100 can be fully utilized, improving space utilization and facilitating the miniaturization design of the battery device 100. The second heat exchanger is located between the battery pack 2 and the housing 1, which also helps to maintain the temperature of the pouch battery cells 22 within a suitable range, improving the reliability of the battery device 100. Heat transfer through the second heat exchanger can further enhance the thermal management capability of the battery device 100, helping to maintain its internal temperature within a reasonable range during operation, thereby improving the working efficiency and stability of the battery device 100.

[0153] For example, a second heat exchanger may be provided between the top plate 13 of the housing 1 and the battery pack 2, and / or a second heat exchanger may be provided between the bottom plate 14 of the housing 1 and the battery pack 2, and / or at least one side beam 151 of the frame 15 of the housing 1 and the battery pack 2 may be provided with a second heat exchanger.

[0154] In some embodiments of this application, the soft-pack battery cell 22 is a ternary battery cell, and the housing 21 of the battery pack 2 wraps around the three peripheral sides of the multiple soft-pack battery cells 22. The housing wall of the housing 21, which is disposed opposite to its open end, is provided with a weak part 210.

[0155] In the above technical solution, the weak part 210 can guide the gas discharged during thermal runaway expansion and depressurization of the ternary battery cell, reduce the risk of gas erratic movement affecting the surrounding ternary battery cells, and thus reduce the risk of severe thermal runaway of the battery pack 2 composed of ternary battery cells. This is beneficial to the thermal runaway management of the battery pack 2 and improves the reliability of the battery pack 2 composed of ternary battery cells.

[0156] In some embodiments of this application, the pouch cell 22 is any one of a lithium iron phosphate cell, a ternary lithium battery cell, and a solid-state battery cell. 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 an all-solid-state battery cell.

[0157] In the above technical solutions, the use of the aforementioned types of pouch battery cells 22 provides more design options for the battery device 100 to meet different usage requirements. Specifically, the pouch battery cell 22 can be a lithium iron phosphate battery cell, which has advantages such as high reliability, long cycle life, light weight, large capacity, and low internal resistance; a ternary lithium battery cell, which has advantages such as high energy density and good electrochemical performance; or a solid-state battery cell, which has advantages such as high energy density, high reliability, light weight, and good high and low temperature performance.

[0158] In some embodiments of this application, the soft-pack battery cell 22 is a lithium iron phosphate battery cell, and the ratio of the amount of positive active material, binder and conductive agent in the positive electrode material of the soft-pack battery cell 22 is 96:(1-3):(1-3); the soft-pack battery cell 22 is a ternary battery cell, and the ratio of the amount of the amount of positive active material, binder and conductive agent in the positive electrode material of the soft-pack battery cell 22 is 96:(2-3):(1-2).

[0159] In the above technical solutions, when the pouch battery cell 22 is a lithium iron phosphate battery cell, a high proportion of positive electrode active material means that more substances capable of electrochemical reactions can be accommodated within a limited electrode assembly. This is beneficial for increasing the capacity and energy density of the battery device 100, enabling the lithium iron phosphate battery cell to output higher power while maintaining a relatively small volume and weight, meeting the application scenarios with certain energy density requirements. Using the above-mentioned range for the amount of binder and conductive agent can reduce the cost of auxiliary materials, thereby reducing the overall cost of the battery device 100. When the pouch battery cell 22 is a ternary battery cell, due to the relatively complex structure and surface properties of ternary materials, using the above-mentioned proportions of positive electrode active material, binder, and conductive agent helps to ensure good adhesion between positive electrode active material particles and between the active material and the current collector, thereby improving the mechanical stability and integrity of the electrode assembly. This helps to reduce the risk of active material detachment and electrode pulverization during charging and discharging, and extends the cycle life of the battery device 100.

[0160] In some embodiments, the positive electrode of the pouch cell 22 can be a positive electrode sheet, which can include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector, the positive electrode film layer including a positive active material.

[0161] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0162] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, titanium, silver-surfaced aluminum, or stainless steel can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0163] As an example, when the pouch cell 22 in this embodiment is a lithium-ion battery, the positive electrode active material may include at least one of the following materials: phosphate, layered transition metal oxide, and their respective modified compounds; optionally, the positive electrode active material may include layered transition metal oxide and their respective modified compounds, which is beneficial to improving the energy density of the pouch cell 22. However, this application is not limited to these materials, and other conventional materials that can be used as the positive electrode film layer of a battery may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0164] Examples of phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0165] Layered transition metal oxides include those with the general formula Li a Ni b Co c M d O e A f At least one of the compounds and their modified compounds. 0.8 ≤ a ≤ 1.2, 0.3 ≤ b < 1, 0 < c < 1, 0 < d < 1, 1 ≤ e ≤ 2, 0 ≤ f ≤ 1, M includes at least one of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, and A includes at least one of N, F, S, and Cl. Optionally, 0.5 ≤ b < 1, and further optionally, 0.75 ≤ b ≤ 0.98.

[0166] Examples of layered transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 LiNi 0.9 Co 0.05 Mn 0.05 O2 (also known as Ni90), lithium nickel cobalt aluminum oxide (such as LiNi) 0.80 Co 0.15 Al 0.05At least one of O2 and its modified compounds.

[0167] When the soft-pack battery cell 22 in this application embodiment is a sodium-ion battery, the positive electrode active material may include, but is not limited to, at least one of sodium-containing transition metal oxides, polyanionic materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian blue materials.

[0168] As an example, positive electrode active materials for sodium-ion batteries may include NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, and NaNi 1 / 2 Ti 1 / 2 O2, NaNi 1 / 2 Mn 1 / 2 O2, Na 2 / 3 Fe 1 / 3 Mn 2 / 3 O2, NaNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, NaFePO4, NaMnPO4, NaCoPO4, Prussian blue materials, with the general formula X p M' q (PO4) r O x Y 3-x At least one of the materials in general formula X. p M' q (PO4) r O x Y 3-x In the given information, 0 < p ≤ 4, 0 < q ≤ 2, 1 ≤ r ≤ 3, 0 ≤ x ≤ 2, X includes at least one of H+, Li+, Na+, K+ and NH4+, M' is a transition metal cation, optionally at least one of V, Ti, Mn, Fe, Co, Ni, Cu and Zn, and Y is a halide anion, optionally at least one of F, Cl and Br.

[0169] In the embodiments of this application, the modified compounds of the above-mentioned positive electrode active materials can be doped and / or surface coated to modify the positive electrode active materials, such as carbon coating modification, fast ion conductor coating modification, etc.

[0170] During the charging and discharging process of the pouch cell 22, active ions such as Li are deintercalated and consumed. The molar content of Li in the pouch cell 22 varies when it is discharged to different states. In the examples of positive electrode active materials in this application, the molar content of Li refers to the initial state of the material, i.e., the state before feeding. When the positive electrode active material is applied to the battery system, the molar content of Li may change after charge-discharge cycles.

[0171] In the examples of positive electrode active materials in this application, the molar content of oxygen (O) is only a theoretical value. Oxygen release from the crystal lattice will cause the molar content of oxygen (O) to change. In reality, the molar content of oxygen (O) will fluctuate.

[0172] In this embodiment, the elemental content in the positive electrode active material is defined in a way known in the art and can be detected using equipment and methods known in the art. For example, referring to EPA 6010D-2014, it can be measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, instrument model: Thermo ICAP7400). First, 0.4g of the positive electrode active material is weighed and 10ml (50% concentration) of aqua regia is added. Then, it is placed on a plate at 180℃ for 30min. After digestion on the plate, the volume is adjusted to 100mL, and quantitative testing is performed using the standard curve method.

[0173] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, a positive electrode film layer may or may not be provided on the surface of the foamed metal. As an example, lithium source material, potassium metal, or sodium metal may also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0174] In some embodiments, the positive electrode film layer may optionally include a positive electrode conductive agent. This application embodiment does not particularly limit the type of positive electrode conductive agent. As an example, the positive electrode conductive agent includes at least one selected from superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the mass percentage of the positive electrode conductive agent in the positive electrode film layer is ≤5 wt%.

[0175] In some embodiments, the positive electrode film layer may optionally include a positive electrode binder. This application embodiment does not impose any particular limitation on the type of positive electrode binder. As an example, the positive electrode binder may include at least one selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins. In some embodiments, the mass percentage of the positive electrode binder in the positive electrode film layer is ≤5 wt%.

[0176] The positive electrode film is typically formed by coating a positive electrode slurry onto a positive electrode current collector, followed by drying and cold pressing. The positive electrode slurry is usually formed by dispersing the positive electrode active material, optional conductive agent, optional binder, and any other components in a solvent and stirring until homogeneous. The solvent can be N-methylpyrrolidone (NMP), but is not limited to it.

[0177] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, the negative electrode film layer including a negative electrode active material.

[0178] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0179] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0180] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in pouch cell 22. As an example, the negative electrode active material may include at least one of the following materials: carbon materials (e.g., carbon materials include at least one of artificial graphite, natural graphite, soft carbon, and hard carbon), silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may include at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may include at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode films in batteries may also be used. These negative electrode films may be used alone or in combination of two or more.

[0181] In some embodiments, the negative electrode active material includes silicon, which may exist in the form of a silicon-based material, such as elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The introduction of silicon can improve the energy density of the pouch cell 22.

[0182] In some embodiments, the mass content of silicon in the negative electrode film layer is from 1 wt% to 32 wt%, optionally from 2 wt% to 19 wt%, and further optionally from 6 wt% to 13 wt%. In the pouch cell 22 system, when the mass content of silicon is within the above range, the energy density of the pouch cell 22 can be improved.

[0183] In the embodiments of this application, the mass content of silicon in the negative electrode film layer has a meaning known in the art and can be detected using equipment and methods known in the art. For example, the negative electrode sheet can be immersed in a solvent such as water to separate the negative electrode active material from the negative electrode current collector, and the negative electrode active material can be obtained by filtration. The silicon content of the negative electrode active material can be obtained by using an ICAP7400 inductively coupled plasma atomic emission spectrometer from Thermo Fisher Scientific, USA, in accordance with the GB / T30902-2014 standard.

[0184] In some embodiments, the negative electrode film layer may optionally include a negative electrode conductive agent. This application embodiment does not particularly limit the type of negative electrode conductive agent. As an example, the negative electrode conductive agent may include at least one selected from superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the mass percentage of the negative electrode conductive agent in the negative electrode film layer is ≤5 wt%.

[0185] In some embodiments, the negative electrode film layer may optionally include a negative electrode binder. This application embodiment does not impose any particular limitation on the type of negative electrode binder. As an example, the negative electrode binder may include at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS). In some embodiments, the mass percentage of the negative electrode binder in the negative electrode film layer is ≤5%.

[0186] In some embodiments, the negative electrode film may optionally include other additives. As an example, other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC-Na), PTC thermistor materials, etc. In some embodiments, the mass percentage of other additives in the negative electrode film is ≤2 wt%.

[0187] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0188] In some embodiments, the separator includes a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0189] This application does not impose any particular restrictions on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0190] In some embodiments, the material of the separator may include one or more of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0191] In some embodiments, the separator may include a porous base membrane and a coating disposed on at least one side of the porous base membrane, the coating including at least one of inorganic or organic particles. The porous base membrane may include one or more of polyethylene and polypropylene.

[0192] Inorganic particles possess good heat resistance, which can improve the overall heat resistance of the separator. Within the operating voltage range of sodium-ion batteries, inorganic particles essentially do not undergo oxidation and reduction reactions with metal dendrites. In other words, inorganic particles are configured to prevent oxidation and reduction reactions with alkali metals and / or alkaline earth metals at the nominal voltage of sodium-ion batteries.

[0193] 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.

[0194] In some embodiments, the organic particles include at least one of polystyrene, polyethylene, polyimide, melamine resin, phenolic resin, polypropylene, polyester (e.g., polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate), polyphenylene sulfide, polyarylamide, polyamide-imide, polyimide, copolymers of butyl acrylate and ethyl methacrylate, and mixtures thereof.

[0195] In some embodiments, the pouch cell 22 further includes an electrolyte.

[0196] During the charging and discharging process of a single battery cell, active ions repeatedly insert and extract between the positive and negative electrode plates, while the electrolyte acts as a conductor for these active ions. This application does not impose any particular limitation on the type of electrolyte; it can be selected according to actual needs. The electrolyte includes an electrolyte salt and a solvent. The types of electrolyte salt and solvent are not specifically limited and can be selected according to actual requirements.

[0197] In some embodiments, the electrolyte may optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, and additives that improve battery low-temperature power performance.

[0198] For example, the additives include at least one of the following: cyclic carbonate compounds containing unsaturated bonds, sulfate compounds, sulfite compounds, sulfonyl lactone compounds, disulfonic acid compounds, nitrile compounds, aromatic compounds, isocyanate compounds, phosphonitrile compounds, acid anhydrides, cyclic acid anhydride compounds, phosphite compounds, phosphate compounds, borate esters, and carboxylic acid esters.

[0199] It is understandable that when the pouch cell 22 is a lithium iron phosphate battery cell, the positive electrode material of the pouch cell 22 has the following proportions: the positive electrode active material accounts for 96 parts of the total weight of the positive electrode material; the binder accounts for 1 to 3 parts of the total weight of the positive electrode material (for example, it may include but is not limited to 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, etc.); and the conductive agent accounts for 1 to 3 parts of the total weight of the positive electrode material (for example, it may include but is not limited to 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, etc.).

[0200] For example, when the pouch cell 22 is a lithium iron phosphate battery cell, the positive electrode active material is LFP (which can refer to LiFePO4, i.e., lithium iron phosphate), the binder can be PVDF (polyvinylidene fluoride), and the conductive agent can be conductive carbon black. The ratio of LFP:PVDF:conductive carbon black can be 96:2:2, meaning that the total weight of the positive electrode active material is divided into 100 parts, with LFP accounting for 96 parts, PVDF accounting for 2 parts, and conductive carbon black also accounting for 2 parts. The weight unit of the positive electrode active material can be grams.

[0201] When the pouch cell 22 is a ternary lithium battery cell, in the positive electrode material of the pouch cell 22, the positive electrode active material accounts for 96 parts of the total weight of the positive electrode material, the binder accounts for 2 to 3 parts of the total weight of the positive electrode material (for example, including but not limited to 2, 2.2, 2.5, 2.8, 3, etc.), and the conductive agent accounts for 1 to 2 parts of the total weight of the positive electrode material (for example, including but not limited to 1, 1.2, 1.5, 1.8, 2, etc.). The ternary lithium battery cell can be, but is not limited to, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, etc.

[0202] For example, the ternary material of the ternary battery cell can be an octet LiNi. 0.8 Co 0.1 Mn 0.1The weight ratio of O2, positive electrode active material, binder, and conductive agent is 96:2.5:1.5, meaning the total weight of the positive electrode material is divided into 100 parts. (This refers to the octet LiNi...) 0.8 Co 0.1 Mn 0.1 The composition of O2 is 96 parts, the composition of adhesive is 2.5 parts, and the composition of conductive agent is 1.5 parts.

[0203] Secondly, embodiments of this application provide an electrical device 1000, including the aforementioned battery device 100, which is used to provide electrical energy.

[0204] In the above technical solution, since the battery device 100 has high reliability, the use of the battery device 100 can improve the power reliability of the power-consuming device 1000.

[0205] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0206] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery device, wherein, include: The housing has a receiving cavity and a discharge cavity, the discharge cavity being disposed around the outer periphery of the receiving cavity, and the discharge cavity communicating with the receiving cavity through a connecting hole; A battery pack is disposed within the receiving cavity and includes a housing and a plurality of pouch cell batteries housed in the housing. The housing has a weak portion configured to release internal pressure from the pouch cell batteries.

2. The battery device of claim 1, wherein, The housing has a U-shaped mounting cavity. The U-shaped mounting cavity has a first open side and a closed side disposed opposite to each other, and the closed side is provided with the 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 the weak part, and the tabs of the soft-pack battery cells extend out of the housing from the corresponding weak part.

3. The battery device according to claim 1 or 2, wherein The weak portion is configured as a pressure relief hole; or, the weak portion is configured as a groove; or, the weak portion is configured as a weakening portion.

4. The battery device according to any one of claims 1 to 3, wherein, If the volumetric energy density ρ of the pouch cell is ≥390Wh / L, then the opening area S of the connecting hole is ≥100cm². 2 The number of connecting holes n≥8; The volume energy density of the soft package battery cell is less than 390 Wh / L, the opening area of the communication hole is 100 cm 2 > S is greater than or equal to 55 cm 2 , and the number of communication holes is 8 > n > 4.

5. The battery device according to any one of claims 1 to 4, wherein Also includes: A first protective component is disposed in the discharge chamber. The first protective component is opposite to and spaced apart from the connecting hole. The high temperature resistance of the first protective component is better than that of the housing.

6. The battery device of claim 5, wherein, The connecting holes are multiple and spaced apart along the surrounding direction of the discharge chamber, and each connecting hole corresponds to one of the first protective components.

7. The battery device according to claim 5 or 6, wherein On a preset plane, the orthographic projection of the wall of the connecting hole is located within the orthographic projection range of the first protective component, and the preset plane is perpendicular to the axis of the connecting hole.

8. The battery device of claim 7, wherein, On the preset plane, the minimum distance x between the orthographic projection of the wall of the connecting hole and the outer contour of the orthographic projection of the first protective member is ≥5mm.

9. The battery device according to any one of claims 5 to 8, wherein, The first protective component is integrated into the housing; or, The first protective component is fixed to the inner wall of the discharge chamber.

10. The battery device according to any one of claims 5 to 9, wherein, The first protective component includes multiple protective layers arranged sequentially along the axial direction of the connecting hole. The materials of the multiple protective layers are different, and among two adjacent protective layers, the protective layer adjacent to the connecting hole has better high-temperature resistance than the protective layer far from the connecting hole.

11. The battery device according to any one of claims 5 to 10, wherein The first protective component is a ceramic composite material, a mica component, a glass fiber component, or a coating disposed on the inner wall of the discharge chamber.

12. The battery device according to any one of claims 5 to 11, wherein, The first protective component is formed as a sheet structure, and the thickness of the first protective component is t, where 0.3mm≤t≤3mm.

13. The battery device according to any one of claims 1 to 12, wherein The housing has weak portions at both ends in the first horizontal direction, and a storage groove is formed at the bottom of the housing corresponding to the end where the weak portion is located. The bottom wall of the storage groove is lower than the soft-pack battery cell.

14. The battery device of claim 13, wherein, The individual pouch battery cells are positioned above the opening of the storage slot.

15. The battery device according to claim 13 or 14, wherein The bottom of the housing has an opening, and the bottom of the receiving cavity has a supporting protrusion. The supporting protrusion supports the soft-pack battery cell and is glued to the soft-pack battery cell. The housing forms a receiving groove with the groove opening facing downward between the two storage slots. The opening is formed on the top wall of the receiving groove. At least a portion of the supporting protrusion is received in the receiving groove and abuts against the groove wall of the receiving groove.

16. The battery device of any one of claims 1 to 15, wherein, Also includes: A pressure relief structure is provided on one side of the housing in the second horizontal direction, or on the bottom side of the housing. The pressure relief structure is 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 of claim 16, wherein, The distance y between the pressure relief structure and the connecting hole in the direction surrounding the discharge chamber is ≥10cm.

18. The battery device of claim 16 or 17, wherein, The discharge chamber includes a first discharge section and a second discharge section that are bent and connected. The second discharge section is connected to the connecting hole through the first discharge section, and the pressure relief structure is provided on the second discharge section.

19. The battery device according to any one of claims 16 to 18, wherein, When the volumetric energy density ρ of the soft-pack battery cell is ≥390Wh / L, the number of pressure relief structures is multiple; When the volumetric energy density ρ of the pouch cell is less than 390Wh / L, the number of pressure relief structures is one.

20. The battery device of any one of claims 1-19, wherein, The housing includes a top plate, a bottom plate, and a frame. The frame surrounds the bottom plate and defines the receiving cavity together with the bottom plate and the top plate. The discharge cavity is formed within the frame, and the connecting hole is formed on the inner peripheral wall of the frame.

21. The battery device of claim 20, wherein, The frame includes a plurality of side beams connected end to end, and at least a portion of the plurality of side beams is hollow to define the discharge chamber.

22. The battery device of claim 21, wherein, The discharge chamber includes a first discharge section and a second discharge section that are bent and connected. The plurality of side beams include two first side beams arranged opposite each other along a first horizontal direction and two second side beams arranged opposite each other along a third horizontal direction. Each first side beam is hollow to define the first discharge section, and each second side beam is hollow to define the second discharge section. The inner wall of each first side beam has a plurality of connecting holes.

23. The battery device of claim 22, wherein, The pressure relief structure is provided on the top of the housing, and the battery device further includes: A second protective component is disposed between the top plate and the battery pack to separate the pressure relief structure from the top plate.

24. The battery device of any one of claims 20-23, wherein, The battery pack comprises multiple packs, and the battery device further includes at least one of a first heat exchanger and a second heat exchanger, wherein the at least one of the first heat exchanger and the second heat exchanger is used for heat exchange with the individual pouch battery cells. The first heat exchanger is located between two adjacent battery packs, and the second heat exchanger is located between the battery pack and the housing.

25. The battery device of any one of claims 1-24, wherein, The soft-pack battery cell can be any one of lithium iron phosphate battery cell, ternary battery cell, and solid-state battery cell.

26. The battery device of claim 25, wherein, The soft-pack battery cell is a lithium iron phosphate battery cell, and the ratio of the positive electrode active material, binder, and conductive agent in the positive electrode material of the soft-pack battery cell is 96:(1-3):(1-3); the soft-pack battery cell is a ternary battery cell, and the ratio of the positive electrode active material, binder, and conductive agent in the positive electrode material of the soft-pack battery cell is 96:(2-3):(1-2).

27. An electrical device, comprising: Includes the battery device according to any one of claims 1-26.

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