Battery device and electric appliance

Abstract

The application relates to the battery technical field and provides a battery device and a power utilization equipment, the battery device comprising a battery monomer assembly and a pad body assembly, the pad body assembly being arranged between at least two adjacent battery monomers, the pad body assembly comprising a first structure layer and second structure layers on opposite sides of the first structure layer, the first structure layer comprising a phase change layer, and the second structure layers comprising at least one of a mica layer, a graphene layer, a ceramic layer and a composite material layer; the thermal conductivity of the second structure layer is greater than or equal to 1 W / (m*K). In a thermal runaway scene, the second structure layer can block the damage of the spray valve material to the first structure layer and the battery monomer, meanwhile, the second structure layer can rapidly conduct heat to the first structure layer, and the first structure layer absorbs heat during the phase change process, so that the temperature of the thermal runaway battery monomer is reduced, and the normal battery monomers adjacent to the thermal runaway battery monomer are less affected by the high temperature of the spray valve material, thereby effectively hindering the heat diffusion.

Description

Technical Field

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

[0002] Battery devices are widely used in vehicles to provide them with electric power. Moreover, to meet the high power demands of vehicles, battery devices are generally used as the power source for vehicles.

[0003] A battery device is composed of multiple battery cells. For battery cells with high energy density, the residual energy after thermal runaway is relatively large. When one battery cell experiences thermal runaway, its heat will rapidly and continuously conduct to adjacent battery cells, eventually causing thermal diffusion throughout the entire battery device. Therefore, it is urgent to mitigate the problem of thermal diffusion during thermal runaway of a battery device. Utility Model Content

[0004] The purpose of this application is to provide a battery device and electrical equipment that aims to solve the problem of thermal runaway in existing battery devices.

[0005] To achieve the above objectives, the technical solution adopted in the embodiments of this application is as follows:

[0006] In a first aspect, embodiments of this application provide a battery device, including:

[0007] A battery cell assembly, the battery cell assembly comprising a plurality of battery cells stacked along a first direction, the first direction being the thickness direction of the battery cells;

[0008] A cushion assembly is disposed between at least two partially adjacent battery cells. The cushion assembly includes a first structural layer and a second structural layer disposed on opposite sides of the first structural layer along the first direction. The first structural layer includes a phase change layer, and the second structural layer includes at least one of a mica layer, a graphene layer, a ceramic layer, and a composite material layer. The thermal conductivity of the second structural layer is ≥1 W / (m·K).

[0009] The beneficial effects of the embodiments of this application are as follows: The battery device provided in the embodiments of this application provides a pad assembly between each battery cell. The pad assembly includes a first structural layer and a second structural layer, wherein the second structural layer has the functions of protection and heat conduction. Specifically, in a thermal runaway scenario, the second structural layer of the pad assembly allows heat to pass through and be conducted to the first structural layer quickly, while the first structural layer absorbs heat during the phase transition process, thereby reducing the temperature of the thermally runaway battery cell. Furthermore, the normal battery cells adjacent to the thermally runaway battery cell are less affected by the high temperature of the ejector valve, thus effectively hindering heat diffusion.

[0010] In some embodiments, the first structural layer includes a phase change body and a covering layer covering the outside of the phase change body, each of the second structural layers is disposed on the covering layer, and each of the second structural layers is disposed on opposite sides of the phase change body.

[0011] By adopting the above technical solution, the phase change subject is wrapped with a coating layer to meet the state changes of the phase change subject during the phase change process.

[0012] In some embodiments, the pad assembly further includes an encapsulation shell covering the outer side of the second structural layer and the outer side of the first structural layer, the encapsulation shell being connected to the battery cell.

[0013] By adopting the above technical solution, the second structural layer and the first structural layer are encapsulated using a packaging shell to fix the second structural layer and the first structural layer.

[0014] In some embodiments, the battery device includes an adhesive element, through which the encapsulation housing is attached to the battery cell.

[0015] By adopting the above technical solution, the pad assembly and the battery cell are connected by adhesive bonding.

[0016] In some embodiments, the encapsulation housing includes an encapsulation body covering the corresponding second structural layer and an encapsulation edge connected to each of the encapsulation bodies. The encapsulation body has a receiving space and an opening end communicating with the receiving space, and the encapsulation edge is used to seal the opening end.

[0017] By adopting the above technical solution, the second structural layer is covered by the encapsulation body, and the edges of the second structural layer and the first structural layer are sealed by the encapsulation edge.

[0018] In some embodiments, the encapsulation housing includes an encapsulation body covering one of the second structural layers, two first encapsulation sides, and two second encapsulation sides. The encapsulation body has two opposing first sides and two second sides connected to each of the first sides. The two first encapsulation sides are disposed on corresponding first sides, folded towards each other and covering the other second structural layer, and the two first encapsulation sides are at least partially stacked. The two second encapsulation sides are disposed on corresponding second sides, folded towards each other and covering each of the first encapsulation sides.

[0019] By adopting the above technical solution, one of the second structural layers is covered by the encapsulation body, and the two first encapsulation sides are folded towards each other, and the two second encapsulation sides are folded towards each other to cover another second structural layer, and the edges of the second structural layer and the first structural layer are sealed.

[0020] In some embodiments, the thickness of the second structural layer is 0.1 mm to 2 mm; and / or,

[0021] The thickness of the first structural layer is 0.1mm to 8mm.

[0022] By adopting the above technical solution, the thickness of the second structural layer and the thickness of the first structural layer are selected according to actual usage requirements.

[0023] In some embodiments, the thickness of the second structural layer is 0.2 mm to 0.5 mm; and / or,

[0024] The thickness of the first structural layer is 2mm to 5mm.

[0025] By adopting the above technical solution, the thickness of the second structural layer and the thickness of the first structural layer can be further selected according to actual usage requirements.

[0026] In some embodiments, a pad assembly is provided between each pair of adjacent battery cells.

[0027] By adopting the above technical solution, each battery cell can be thermally insulated and protected, further reducing the probability of heat diffusion.

[0028] Secondly, embodiments of this application also provide an electrical device, including the battery device as described above, which is used to provide electrical energy.

[0029] It is understood that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of the electrical equipment provided in the embodiments of this application;

[0032] Figure 2This is a schematic diagram of the structure of the battery device provided in the embodiments of this application;

[0033] Figure 3 An exploded view of a single battery cell provided in an embodiment of this application;

[0034] Figure 4 This is a schematic diagram of the structure of the battery cell and the pad assembly of the battery device provided in the embodiments of this application;

[0035] Figure 5 A left view of the battery cell and pad assembly of the battery device provided in the embodiments of this application;

[0036] Figure 6 A cross-sectional view of the pad assembly of the battery device provided in the embodiments of this application after removing the encapsulation shell;

[0037] Figure 7 A cross-sectional view of the pad assembly and adhesive of the battery device provided in the embodiments of this application;

[0038] Figure 8 A schematic diagram of the encapsulation shell of the pad assembly of the battery device provided in an embodiment of this application;

[0039] Figure 9 The time-temperature curves of the battery device provided in the embodiments of this application and the battery device in the comparative example during thermal runaway are shown.

[0040] The following are the labeling elements in the figure:

[0041] 1000, vehicle; 200, controller; 300, motor;

[0042] 100. Battery assembly; 10. Housing; 11. First housing; 12. Second housing; 20. Battery cell; 21. End cap; 22. Casing; 23. Electrode assembly; X, First direction;

[0043] 30. Pad assembly; 31. First structural layer; 32. Second structural layer; 311. Phase change body; 312. Covering layer; 33. Encapsulation shell; 331. Encapsulation body; 332. Encapsulation edge; 333. First encapsulation side; 334. Second encapsulation side; 331a. First side; 331b. Second side;

[0044] 40. Adhesive components. Detailed Implementation

[0045] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0046] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0048] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0049] In related technologies, battery devices are composed of multiple battery cell components. For battery cells with high energy density, the residual energy after thermal runaway is large. When one battery cell experiences thermal runaway, its heat will be rapidly and continuously conducted to adjacent battery cells, eventually causing thermal diffusion of the entire battery device.

[0050] To address the aforementioned issues, heat insulation pads are typically placed between battery cells. These pads utilize their heat resistance and impact resistance to block the ejected material and accompanying high temperatures from runaway battery cells, thereby effectively protecting adjacent battery cells.

[0051] However, current thermal insulation pads only serve as a barrier, providing good protection for adjacent battery cells that have not yet experienced thermal runaway. However, they cannot effectively intervene in the thermal runaway of battery cells that have already occurred, which makes it very easy for heat to spread within the battery device.

[0052] In view of this, this application provides a battery device in which a pad assembly is disposed between individual battery cells. The pad assembly includes a first structural layer and second structural layers disposed on opposite sides of the first structural layer. In a thermal runaway scenario, the second structural layer of the pad assembly can effectively prevent the ejector material from damaging the first structural layer and adjacent battery cells. At the same time, the second structural layer allows heat to pass through and be conducted to the first structural layer quickly, while the first structural layer absorbs heat during the phase transition process, thereby reducing the temperature of the thermally runaway battery cells. Furthermore, the normal battery cells adjacent to the thermally runaway battery cells are less affected by the high temperature of the ejector material, thus effectively hindering heat diffusion.

[0053] The battery cells disclosed in this application can be used in electrical devices that use battery devices as power sources or in various energy storage systems that use battery devices as energy storage elements. Electrical devices can be, but are 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, etc.

[0054] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0055] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 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 1000 during starting, navigation, and driving.

[0056] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0057] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells 20, which are connected in series, parallel, or mixed connection via a busbar.

[0058] In some embodiments, the battery cell assembly is typically formed by arranging a plurality of battery cells 20.

[0059] As an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 20 into a single module. As an example, the battery module can be formed by bundling multiple battery cells 20 together with cable ties.

[0060] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 10 and one or more battery cell assemblies housed in the housing 10.

[0061] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing 10 by fixing the battery module in the housing 10.

[0062] As an example, the battery cell assembly can also be housed in the housing 10 by directly fixing multiple battery cells 20 to the housing 10.

[0063] As an example, the housing 10 may include a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are fastened together to form a closed space inside the housing 10 to house the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 11 may be a top cover or a bottom plate.

[0064] As an example, the housing 10 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 10 forms an enclosed space to accommodate the battery cell assembly.

[0065] In some embodiments, the housing 10 may be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 may be at least a portion of the floor of the vehicle 1000, or a portion of the housing 10 may be at least a portion of the crossbeams and longitudinal beams of the vehicle 1000.

[0066] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells 20, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles, etc.

[0067] In this embodiment of the application, the battery cell 20 can be a secondary battery, which refers to a battery cell 20 that can be used again after the battery cell has been discharged by recharging to activate the active materials.

[0068] The battery cell 20 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0069] Please refer to Figure 3 , Figure 3 This is an exploded structural diagram of a battery cell 20 provided in some embodiments of this application. The battery cell 20 refers to the smallest unit constituting the battery device 100. For example... Figure 3 The battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0070] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved reliability. Functional components such as electrode terminals can be provided on end cap 21. Electrode terminals can be used for electrical connection with electrode assembly 23 for outputting or inputting electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as, but not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0071] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 closes the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 can be integrated. Specifically, the end cap 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the end cap 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The housing 22 can be made of various materials, such as, but not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0072] Electrode assembly 23 is the component in the battery cell 20 where electrochemical reactions occur. The casing 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 23, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0073] Please refer to Figures 4 to 6 The battery device 100 provided in this application embodiment includes a battery cell assembly and a pad assembly 30.

[0074] The battery cell assembly includes a plurality of battery cells 20 stacked along a first direction, the first direction being the thickness direction of the battery cells 20; a pad assembly 30 is disposed between at least two partially adjacent battery cells 20, the pad assembly 30 includes a first structural layer 31, and a second structural layer 32 disposed on opposite sides of the first structural layer 31 along the first direction, the first structural layer 31 includes a phase change layer, and the second structural layer 32 includes at least one of a mica layer, a graphene layer, a ceramic layer, and a composite material layer; the thermal conductivity of the second structural layer 32 is ≥1 W / (m·K).

[0075] Understandably, the second structural layer 32 serves a thermal conductivity function, which means it can rapidly conduct the heat generated by the thermally runaway battery cell 20 to the first structural layer 31. Therefore, the second structural layer 32 has thermal conductivity. This thermal conductivity refers to the material's ability to transfer heat, and the thermal conductivity coefficient is the most crucial physical indicator for measuring thermal conductivity. The physical meaning of the thermal conductivity coefficient is that, under stable heat transfer conditions, a 1-meter-thick material with a temperature difference of 1°C on both sides can transfer heat through a 1-square-meter area in 1 second, with the unit being W / (m·K). Furthermore, the higher the value, the stronger the thermal conductivity. In this embodiment, the thermal conductivity coefficient of the second structural layer 32 should be greater than or equal to 1 W / (m·K).

[0076] For example, the material of the second structural layer 32 can be mica. Based on the type of mica, it can be classified as phlogopite mica paper or muscovite mica paper; based on structure and process, it can be classified as single-layer mica paper, multi-layer composite mica paper, and mica-glass fiber composite paper. Of course, the material of the second structural layer 32 can also be graphene composite material, ceramic fiber reinforced composite material, aramid fiber composite material, metal-ceramic composite material, modified aluminosilicate fiberboard, polyimide composite material, high-density polyethylene, etc.

[0077] Specifically, the second structural layer 32 includes any one or more of the following: mica layer, graphene layer, ceramic layer, and composite material layer.

[0078] Understandably, a mica layer is a layered structure of mica material, such as phlogopite, muscovite, etc., and can also be selected as a single-layer mica or multi-layer composite mica as needed.

[0079] Graphene layers are layered structures made primarily of graphene. The honeycomb structure of graphene gives the material extremely high strength and toughness, and it can absorb impact energy. It can remain stable in the range of 300℃ to 500℃, and some modified graphene composites can reach even higher temperatures. It can also form a dense carbon layer, which blocks oxygen and inhibits combustion.

[0080] The ceramic layer is a layer structure with ceramics as the main raw material, such as silicon carbide (SiC) ceramics, zirconium oxide (ZrO2), etc.

[0081] Composite material layers are layered structures made of composite materials, such as aramid fiber composites, metal-ceramic composites, and polyimide composites.

[0082] The first structural layer 31 includes a phase change layer, which is a layer structure that can absorb or release a large amount of heat through its own physical state (phase change), thereby playing a role in storing thermal energy or regulating temperature. Therefore, the first structural layer 31 can absorb the heat released by the thermally runaway battery cell 20 through the second structural layer 32, so as to effectively block most of the heat from being transferred to the adjacent battery cell 20.

[0083] For example, the material of the first structural layer 31 can be classified according to the phase change type, such as solid-liquid phase change materials, solid-solid phase change materials, and liquid-gas phase change materials. Examples include paraffin wax, fatty acids (such as lauric acid and stearic acid), hydrated salts (such as sodium sulfate decahydrate), and refrigerants (ammonia and Freon). It can also be classified according to the composition of the phase change material, such as inorganic phase change materials, organic phase change materials, and composite phase change materials. Furthermore, it can be classified according to the phase change temperature range, such as medium-temperature phase change materials and high-temperature phase change materials, for example, potassium nitrate (KNO3, phase change temperature 228°C), magnesium hydroxide (Mg(OH)2, phase change temperature 350°C), and metal alloys (such as Sn, phase change temperature 232°C).

[0084] Additionally, for example, a pad assembly 30 may be provided between every two adjacent battery cells 20 to provide thermal insulation protection for each battery cell, further reducing the probability of heat diffusion.

[0085] The battery device provided in this application embodiment includes a pad assembly 30 disposed between each battery cell 20. The pad assembly 30 includes a first structural layer 31 and second structural layers 32 disposed on opposite sides of the first structural layer 31. In a thermal runaway scenario, the second structural layer 32 of the pad assembly 30 allows heat to pass through and be conducted to the first structural layer 31 quickly. The first structural layer 31 absorbs heat during the phase transition process, thereby reducing the temperature of the thermally runaway battery cell 20. Furthermore, the normal battery cells 20 adjacent to the thermally runaway battery cell 20 are less affected by the high temperature of the ejector material, thus effectively hindering heat diffusion.

[0086] In some embodiments, the second structural layer 32 is also used to protect the first structural layer 31.

[0087] Here, protection refers to blocking the ejector material from the thermal runaway battery cell 20 to reduce its impact on adjacent battery cells 20. Therefore, the second structural layer 32 also possesses several important characteristic properties, namely impact resistance, high-temperature resistance, and fire resistance. Impact resistance refers to the material's impact strength, measured by the energy absorbed per unit area at fracture when a standard specimen is broken by a pendulum or hammer of specified shape and weight. The unit is typically kJ / m², and can be found in the national standard GB / T 9639.1. High-temperature resistance can be found in the national standard GB / T 11021-2021. Fire resistance refers to the material's ability to resist combustion, prevent flame spread, and reduce fire hazards when exposed to a fire source or high temperature. Fire resistance can be found in the national standard GB / T 9978.1.

[0088] In some embodiments, the energy density of the battery cell 20 is greater than or equal to 240Wh / kg.

[0089] Understandably, the high-energy-density battery cell 20 experiences significant weight loss during thermal runaway, and the valves depress rapidly.

[0090] For example, the battery cell 20 can be a high-nickel ternary lithium battery cell 20. A high-nickel ternary lithium battery cell 20 means that the positive electrode material of the battery is composed of three metal elements: nickel (Ni), cobalt (Co), and manganese (Mn) or nickel (Ni), cobalt (Co), and aluminum (Al). Among these three metals, the proportion of nickel (Ni) is very high, usually exceeding 80% in molar ratio.

[0091] In this way, the pad assembly 30 is used to protect the high-energy-density battery cell 20 from thermal runaway, thereby effectively improving the problem of thermal diffusion.

[0092] Please refer to Figure 6 In some embodiments, the thickness H1 of the second structural layer 32 is 0.1 mm to 2 mm.

[0093] Understandably, the thickness of the second structural layer 32 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, etc.

[0094] Please refer to Figure 6 In some embodiments, the thickness H2 of the first structural layer 31 is 0.1 mm to 8 mm.

[0095] Understandably, the thickness of the first structural layer 31 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, etc.

[0096] Thus, the thickness of the second structural layer 32 and the thickness of the first structural layer 31 are selected according to actual usage requirements.

[0097] In some embodiments, the thickness of the second structural layer 32 is 0.2 mm to 0.5 mm.

[0098] Understandably, the thickness of the second structural layer 32 can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc. While meeting the requirements for impact resistance, high temperature resistance, fire resistance, and thermal conductivity, a thinner second structural layer 32 also results in a thinner overall thickness of the pad assembly 30, thus reducing the cumulative thickness of each pad assembly 30 and improving the energy density of the battery device.

[0099] In some embodiments, the thickness of the first structural layer 31 is 2 mm to 5 mm.

[0100] Understandably, the thickness of the first structural layer 31 can be 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm, etc.

[0101] Thus, the thickness of the second structural layer 32 and the thickness of the first structural layer 31 are selected according to actual usage requirements.

[0102] In some embodiments, the second structural layer 32 includes any one or more of a mica layer, a graphene layer, a ceramic layer, and a composite material layer.

[0103] Understandably, a mica layer is a layered structure of mica material, such as phlogopite, muscovite, etc., and can also be selected as a single-layer mica or multi-layer composite mica as needed.

[0104] Graphene layers are layered structures made primarily of graphene. The honeycomb structure of graphene gives the material extremely high strength and toughness, and it can absorb impact energy. It can remain stable in the range of 300℃ to 500℃, and some modified graphene composites can reach even higher temperatures. It can also form a dense carbon layer, which blocks oxygen and inhibits combustion.

[0105] The ceramic layer is a layer structure with ceramics as the main raw material, such as silicon carbide (SiC) ceramics, zirconium oxide (ZrO2), etc.

[0106] Composite material layers are layered structures made of composite materials, such as aramid fiber composites, metal-ceramic composites, and polyimide composites.

[0107] Therefore, the second structural layer 32 can be selected according to actual usage requirements.

[0108] Please refer to Figure 6 In some embodiments, the first structural layer 31 includes a phase change body 311 and a covering layer 312 covering the outside of the phase change body 311. Each second structural layer 32 is disposed on the covering layer 312, and each second structural layer 32 is disposed on opposite sides of the phase change body 311.

[0109] Understandably, the phase change body 311 is the part in the first structural layer 31 where the phase change mainly occurs, while the covering layer 312 is the part used to wrap the phase change body 311 and play a role in fixing the phase change body 311.

[0110] For example, the covering layer 312 may be an aluminum-plastic film, which has ultra-high barrier properties, chemical corrosion resistance, good mechanical properties, reliable encapsulation, and good insulation.

[0111] The phase change host 311 can be potassium nitrate, magnesium hydroxide, or paraffin, etc.

[0112] Thus, the phase change body 311 is wrapped with the coating layer 312 to meet the state changes of the phase change body 311 during the phase change process.

[0113] In some embodiments, the phase change host 311 includes any one or more of inorganic phase change hosts, organic phase change hosts, composite phase change hosts, and nano-reinforced phase change hosts.

[0114] Understandably, inorganic phase change substrates include hydrated salts (such as CaCl2·6H2O, Na2SO4·10H2O), metal alloys (such as tin and lead alloys), and cement-based composite materials (such as gypsum incorporated into phase change microcapsules), which have the advantages of high latent heat, low cost, and good chemical stability.

[0115] Organic phase change substrates include paraffin wax, fatty acids (such as lauric acid and stearic acid), and polyols (such as polyethylene glycol PEG). Their advantages are that they are non-corrosive, have good chemical stability, and are not easily supercooled.

[0116] Composite phase change substrates include paraffin / expanded graphite composite phase change substrates, hydrated salt / clay composite phase change substrates, etc. Their advantage is that they overcome the disadvantages of single materials through composite modification.

[0117] Nanomaterial-enhanced phase change substrates include paraffin / carbon nanotube composite phase change substrates and hydrated salt / nanoclay composite phase change substrates. Their advantage is that the addition of nanomaterials (such as graphene oxide and carbon nanotubes) improves thermal conductivity or stability.

[0118] Thus, the phase change body 311 is selected based on actual usage requirements.

[0119] Please refer to Figure 7In some embodiments, the pad assembly 30 further includes an encapsulation shell 33 covering the outer side of the second structural layer 32 and the outer side of the first structural layer 31, the encapsulation shell 33 being connected to the battery cell 20.

[0120] Understandably, the encapsulation shell 33 is a structural layer used to cover the second structural layer 32 and the first structural layer 31. That is, the encapsulation shell 33 is the outermost layer of the pad assembly 30 and is in direct contact with the battery cell 20.

[0121] For example, the encapsulation housing 33 includes a PET (polyethylene terephthalate) encapsulation housing 33, and then an adhesive can be applied to the surface of the PET encapsulation housing 33 to connect it to the battery cell 20.

[0122] Thus, the second structural layer 32 and the first structural layer 31 are encapsulated using the encapsulation shell 33 to fix the second structural layer 32 and the first structural layer 31.

[0123] Please refer to Figure 7 In some embodiments, the battery device 100 includes an adhesive 40, through which the encapsulation housing 33 is connected to the battery cell 20.

[0124] Understandably, the adhesive component 40 is a structural component used to bond the encapsulation shell 33 to the battery cell 20. Here, the adhesive component 40 can be a double-sided adhesive, an adhesive layer, etc.

[0125] Thus, the pad assembly 30 and the battery cell 20 are connected by adhesive bonding using the adhesive component 40.

[0126] Please refer to Figure 7 In some embodiments, the encapsulation shell 33 includes an encapsulation body 331 covering the corresponding second structural layer 32 and an encapsulation edge 332 connected to each encapsulation body 331. The encapsulation body 331 has a receiving space and an opening end communicating with the receiving space, and the encapsulation edge 332 is used to block the opening end.

[0127] Understandably, the encapsulation body 331 is the part used to cover and enclose the second structural layer 32, and the size and shape of the encapsulation body 331 should be adapted to the size and shape of the second structural layer 32; the encapsulation edge 332 is the part used to cover and enclose the side of the second structural layer 32 and the side of the first structural layer 31.

[0128] For example, the encapsulation body 331 may be an encapsulation sleeve with an opening and a pocket-like structure. The encapsulation edge 332 is disposed at the opening of the encapsulation sleeve. The second structural layer 32 and the first structural layer 31 can enter the encapsulation sleeve through the opening. Then, the encapsulation edge 332 is folded over and the opening is sealed by heat fusion.

[0129] Thus, the second structural layer 32 is covered by the encapsulation body 331, and the edges of the second structural layer 32 and the first structural layer 31 are sealed by the encapsulation edge 332.

[0130] Please refer to Figure 8 In some embodiments, the encapsulation housing 33 includes an encapsulation body 331 covering one of the second structural layers 32, two first encapsulation sides 333, and two second encapsulation sides 334. The encapsulation body 331 has two oppositely disposed first sides 331a and two second sides 331b connected to each of the first sides 331a. The two first encapsulation sides 333 are disposed on the corresponding first sides 331a. The two first encapsulation sides 333 are folded towards each other and cover the other second structural layer 32. Furthermore, the two first encapsulation sides 333 are at least partially stacked. The two second encapsulation sides 334 are disposed on the corresponding second sides 331b. The two second encapsulation sides 334 are folded towards each other and cover each of the first encapsulation sides 333.

[0131] Understandably, in this embodiment, the encapsulation shell 33 encapsulates the second structural layer 32 and the first structural layer 31 by providing encapsulation sides on the sides of the encapsulation body 331.

[0132] The specific encapsulation process is as follows: A "sandwich" structure consisting of two second structural layers 32 and a first structural layer 31 is placed on the encapsulation body 331. At this point, the encapsulation body 331 covers one of the second structural layers 32. Then, the two first encapsulation sides 333 are folded towards each other to cover the other second structural layer 32. The two first encapsulation sides 333 are at least partially overlapped to completely cover the current second structural layer 32. Finally, the two second encapsulation sides 334 are folded towards each other to cover the first encapsulation sides 333. That is, the two first encapsulation sides 333 and the two second encapsulation sides 334 cover the other second structural layer 32. After completing the above steps, the encapsulation shell 33 is heat-sealed.

[0133] Thus, the encapsulation body 331 is used to cover one of the second structural layers 32, and the two first encapsulation sides 333 are folded towards each other, and the two second encapsulation sides 334 are folded towards each other to cover the other second structural layer 32, and the edges of the second structural layer 32 and the first structural layer 31 are sealed.

[0134] Please refer to Figures 4 to 8In one specific embodiment, the battery device 100 provided in this application includes a battery cell assembly and a pad assembly 30. The battery cell assembly includes a plurality of battery cells 20 stacked in layers; the pad assembly 30 is disposed between two adjacent battery cells 20, and the pad assembly 30 includes a first structural layer 31 and second structural layers 32 disposed on opposite sides of the first structural layer 31, with the side of each second structural layer 32 facing away from the first structural layer 31 corresponding to the battery cell 20.

[0135] The thickness H1 of the second structural layer 32 is 0.2mm to 0.5mm; the thickness H2 of the first structural layer 31 is 2mm to 5mm; the second structural layer 32 includes a mica layer.

[0136] The first structural layer 31 includes a phase change body 311 and a covering layer 312 covering the outside of the phase change body 311. Each second structural layer 32 is disposed on the covering layer 312, and each second structural layer 32 is disposed on opposite sides of the phase change body 311.

[0137] The pad assembly 30 also includes an encapsulation shell 33 covering the outer side of the second structural layer 32 and the outer side of the first structural layer 31, and the encapsulation shell 33 is connected to the battery cell 20.

[0138] The battery device 100 includes an adhesive 40, and the encapsulation housing 33 is connected to the battery cell 20 via the adhesive 40.

[0139] The encapsulation housing 33 includes an encapsulation body 331 covering one of the second structural layers 32, two first encapsulation sides 333, and two second encapsulation sides 334. The encapsulation body 331 has two oppositely disposed first sides 331a and two second sides 331b connected to each of the first sides 331a. The two first encapsulation sides 333 are disposed on the corresponding first sides 331a. The two first encapsulation sides 333 are folded towards each other and cover the other second structural layer 32. Furthermore, the two first encapsulation sides 333 are at least partially stacked. The two second encapsulation sides 334 are disposed on the corresponding second sides 331b. The two second encapsulation sides 334 are folded towards each other and cover each of the first encapsulation sides 333.

[0140] In summary, thermal runaway simulation tests were conducted on the current battery device. A pad assembly 30 was placed between each battery cell 20, wherein the second structural layer 32 has a thickness of 0.2 mm and is a mica layer, and the first structural layer 31 has a thickness of 2.1 mm. The battery device in the comparative example did not include the pad assembly 30. When thermal runaway occurred in the battery devices of the embodiments and the comparative example, the temperature of the currently thermally runaway battery cell 20 and the adjacent battery cells 20 were measured to obtain the curves shown in the figure. Figure 9The figures show the time-temperature curves of the battery device provided in this embodiment and the battery device in the comparative example during thermal runaway. In the figures, the red curve represents the time-temperature curve of the battery device in the comparative example during thermal runaway; curve 1 represents the time-temperature curve of the thermally runaway battery cell 20 in the comparative example battery device, and curve 2 represents the time-temperature curve of the battery cell 20 adjacent to the thermally runaway battery cell 20 in the comparative example battery device. In the figures, the blue curve represents the time-temperature curve of the battery device in this embodiment during thermal runaway; curve 3 represents the time-temperature curve of the thermally runaway battery cell 20 in the battery device in this embodiment, and curve 4 represents the time-temperature curve of the battery cell 20 adjacent to the thermally runaway battery cell 20 in the battery device in this embodiment. As can be seen from the figures, when thermal runaway occurs, the temperature of the thermally runaway battery cell 20 in the comparative example rises sharply in a short time. Then, after a short period, the heat diffuses to the adjacent battery cells 20, and the adjacent battery cells 20 also experience thermal runaway, with their temperatures rising sharply in a short time. In this embodiment, when thermal runaway occurs, the cushion assembly 30 can absorb a large amount of heat, so that the temperature of the battery cell 20 adjacent to the thermal runaway battery cell 20 is always kept at around 100°C. Furthermore, the current thermal runaway battery cell 20 also begins to cool down after its temperature rises sharply to 400°C, and the temperature is eventually maintained at around 100°C. This shows that the cushion assembly 30 can also absorb the heat of the thermal runaway battery cell 20, effectively control its temperature, and significantly reduce the probability of heat diffusion.

[0141] Secondly, embodiments of this application also provide an electrical device, including the battery device as described above, which is used to provide electrical energy.

[0142] It is understood that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0143] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A battery device, characterized in that, include: A battery cell assembly, the battery cell assembly comprising a plurality of battery cells stacked along a first direction, the first direction being the thickness direction of the battery cells; A cushion assembly is disposed between at least two adjacent battery cells. The cushion assembly includes a first structural layer and a second structural layer disposed on opposite sides of the first structural layer along the first direction. The first structural layer includes a phase change layer, and the second structural layer includes at least one of a mica layer, a graphene layer, a ceramic layer, and a composite material layer. The thermal conductivity of the second structural layer is ≥1 W / (m·K).

2. The battery device according to claim 1, characterized in that, The first structural layer includes a phase change body and a covering layer covering the outside of the phase change body. In the stacking direction of the battery cell, each second structural layer is disposed on the side of the covering layer opposite to the phase change body.

3. The battery device according to claim 1, characterized in that, The pad assembly further includes an encapsulation shell covering the outer side of the second structural layer and the outer side of the first structural layer, the encapsulation shell being connected to the battery cell.

4. The battery device according to claim 3, characterized in that, The battery device includes an adhesive component, through which the encapsulation housing is connected to the battery cell.

5. The battery device according to claim 3, characterized in that, The encapsulation shell includes an encapsulation body and an encapsulation edge connected to the encapsulation body. The encapsulation body has a receiving space and an opening end communicating with the receiving space. The encapsulation edge is used to seal the opening end.

6. The battery device according to claim 3, characterized in that, The encapsulation shell includes an encapsulation body covering one of the second structural layers, two first encapsulation sides, and two second encapsulation sides. The encapsulation body has two oppositely disposed first sides and two second sides connected to each of the first sides. The two first encapsulation sides are disposed on corresponding first sides. The two first encapsulation sides are folded towards each other and cover the other second structural layer. Furthermore, the two first encapsulation sides are at least partially stacked. The two second encapsulation sides are disposed on corresponding second sides. The two second encapsulation sides are folded towards each other and cover each of the first encapsulation sides.

7. The battery device according to claim 1, characterized in that, The thickness of the second structural layer is 0.1 mm to 2 mm; and / or, The thickness of the first structural layer is 0.1mm to 8mm.

8. The battery device according to claim 7, characterized in that, The thickness of the second structural layer is 0.2mm~0.5mm; and / or, The thickness of the first structural layer is 2mm to 5mm.

9. The battery device according to claim 1, characterized in that, A pad assembly is provided between each pair of adjacent battery cells.

10. An electrical appliance, characterized in that: Includes the battery device as described in any one of claims 1 to 9.

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