Battery devices and power-consuming devices

Abstract

The present application belongs to the field of battery technology, and specifically relates to a battery device and an electrical device. The battery device includes a battery cell and a heat-insulating pad disposed between adjacent battery cells, the heat-insulating pad includes a first surface layer, a second surface layer and a heat-insulating layer disposed between the two surface layers, at least a central position of the heat-insulating layer is provided with a receiving hole, the receiving hole is filled with a heat-absorbing medium, the heat-absorbing medium can absorb heat, when a battery cell has thermal runaway, at least part of the heat generated by it can be absorbed by the heat-absorbing medium in the heat-insulating pad, thereby effectively reducing the heat conducted to the adjacent battery cell, so that the heat-insulating pad can not only prolong the heat transfer time between adjacent battery cells and delay the occurrence speed of thermal runaway of adjacent battery cells, but also reduce the risk of thermal runaway of adjacent battery cells by absorbing heat, thereby helping to improve the thermal stability and reliability of the battery device.

Description

Technical Field

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

[0002] Battery temperature is the most important parameter affecting battery performance and is currently the focus of research in the battery design process.

[0003] A battery cell is the smallest unit that makes up a battery device. When one or more battery cells overheat and thermal runaway occurs, the heat will spread to the surrounding battery cells, causing a large area of ​​battery cells to overheat, thereby causing the battery device to become unstable.

[0004] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a battery device and an electrical device, including but not limited to solving the technical problem of thermal runaway of a single battery cell inside the battery device due to heat diffusion to surrounding battery cells.

[0006] The technical solution adopted in the embodiment of the present application is:

[0007] In a first aspect, a battery device is provided, comprising:

[0008] Multiple battery cells;

[0009] A heat insulation pad is provided between two adjacent battery cells;

[0010] The thermal insulation pad comprises a first surface layer, a second surface layer, and a thermal insulation layer arranged between the first surface layer and the second surface layer, wherein at least a middle portion of the thermal insulation layer is provided with a plurality of receiving holes, and the receiving holes are filled with a heat absorbing medium;

[0011] The thermal insulation pad also includes a first reflecting layer and a second reflecting layer. The first reflecting layer covers the surface of the thermal insulation layer facing the first surface layer, and the second reflecting layer covers the surface of the thermal insulation layer facing the second surface layer. There is a first gap between the first reflecting layer and the first surface layer, and there is a second gap between the second reflecting layer and the second surface layer.

[0012] In the battery device of the embodiment of the present application, a thermal insulation pad is arranged between adjacent battery cells, and the thermal insulation pad includes a first surface layer, a second surface layer and a thermal insulation layer, the thermal insulation layer is arranged between the two surface layers, and a receiving hole is arranged at least in the middle position of the thermal insulation layer, and a heat absorption medium is filled in the receiving hole, and the heat absorption medium can absorb heat. When a battery cell has thermal runaway, at least part of the heat generated by it can be absorbed by the heat absorption medium in the thermal insulation pad, thereby effectively reducing the heat conducted to the adjacent battery cell, so that the thermal insulation pad can not only prolong the heat transfer time between adjacent battery cells and delay the occurrence speed of thermal runaway of adjacent battery cells, but also reduce the heat conduction amount by absorbing heat, thereby reducing the risk of thermal runaway of adjacent battery cells. The thermal insulation pad has good thermal insulation effect and certain heat absorption effect, and can effectively insulate the battery cells adjacent to it, so that the thermal stability of the battery device is improved and the reliability of use is improved.

[0013] On this basis, by covering the first reflective layer and the second reflective layer on the two side surfaces of the thermal insulation layer, the first reflective layer and the second reflective layer cooperate with other parts of the thermal insulation pad (the first surface layer, the second surface layer and the thermal insulation layer) to form a multi-level thermal insulation system. The first surface layer and the second surface layer may play a role of protection and preliminary isolation, while the first reflective layer and the second reflective layer are mainly used to reflect heat, thereby reducing the heat transferred by thermal radiation and reducing the transfer of heat to the thermal insulation layer. The thermal insulation layer further prevents the conduction of heat, thereby further enhancing the thermal insulation performance of the thermal insulation pad. At the same time, a first gap is set between the first reflecting layer and the first surface layer, and a second gap is set between the second reflecting layer and the second surface layer. In this way, when the battery cell expands and squeezes the thermal insulation pad, the middle part of the thermal insulation pad has a larger deformation space due to the existence of the first gap and the second gap. The middle part of the thermal insulation pad can withstand a greater extrusion force to adapt to the larger expansion and deformation that may occur in the middle area of ​​the battery cell, thereby helping to reduce the risk of damage to the thermal insulation pad structure due to large force deformation in the middle area. The service life of the thermal insulation structure is extended, and the thermal insulation effect is improved, so that the adjacent battery cells can be effectively insulated, so that the battery device has higher thermal stability and improved reliability.

[0014] In some embodiments, at least one side surface of the thermal insulation layer is provided with an opening, and along the thickness direction of the thermal insulation pad, the receiving hole is connected to the opening.

[0015] By adopting the technical solution of this embodiment, the accommodating hole is communicated with the first surface layer, or with the second surface layer, or with both side surface layers at the same time. When the battery cell generates heat and conducts it to the surface of the thermal insulation layer close to the battery cell, the accommodating hole is set to be connected with this side surface. In this way, the heat can be more directly transferred to the heat-absorbing medium in the accommodating hole, so that the heat-absorbing medium can absorb heat in time, thereby further improving the thermal insulation effect of the thermal insulation pad.

[0016] In some embodiments, the number of the receiving holes is multiple, and the multiple receiving holes are evenly arranged in the middle of the thermal insulation layer. In this way, multiple receiving holes are evenly arranged in the middle of the thermal insulation pad, so that the heat absorption medium can be evenly distributed in the middle area of ​​the thermal insulation layer, thereby further improving the heat absorption capacity. Exemplarily, the number of receiving holes can be two, or more than two.

[0017] In some embodiments, the heat absorbing medium comprises a solid heat absorbing medium, and the solid heat absorbing medium is at least partially decomposed into a gas when the temperature reaches a threshold value.

[0018] In this embodiment, the solid heat absorbing medium is filled in the receiving holes of the heat insulating layer. At normal temperature, the heat absorbing medium exists in a solid form.

[0019] By adopting the technical solution of this embodiment, the solid heat absorbing medium is filled in the receiving hole of the insulation layer. At normal temperature, the heat absorbing medium exists in a solid form, so that it can be stably filled in the receiving hole, and will not be unevenly distributed or flow out of the receiving hole due to easy flow. When the temperature exceeds a certain threshold, the solid heat absorbing medium is thermally decomposed, thereby absorbing heat faster, and after absorbing heat, the medium directly generates gas from the solid state without or only a small amount of liquid, thereby helping to reduce the risk of short circuit inside the battery device due to the outflow of thermal decomposition products from the insulation pad.

[0020] In some embodiments, the heat absorbing medium includes one or more of carbonate, bicarbonate, phosphate, and hydrogen phosphate.

[0021] By adopting the technical solution of this embodiment, one or more of the above materials are used as heat absorbing media to fill the receiving hole, which decomposes to produce gas when heated. Moreover, when the heat absorbing medium is a mixture of the above substances, since the decomposition temperatures of different substances may be different, their combination can play a heat absorbing role in different temperature ranges, thereby expanding the temperature control range. In addition, different gases have different thermal conductivities and different obstacles to heat transfer. Through reasonable matching, the gas composition in the receiving hole can be made more complex, thereby further reducing the thermal conductivity and enhancing the thermal insulation effect.

[0022] In some embodiments, the heat absorbing medium further includes an adhesive, and the adhesive is mixed with one or more of carbonates, bicarbonates, phosphates, and hydrogen phosphates to allow the heat absorbing medium to adhere to the receiving hole.

[0023] In some embodiments, the adhesive includes one or more of water glass, silica sol, ethyl silicate, polyvinylidene fluoride, polyacrylic acid, and polyvinyl pyrrolidone.

[0024] In some embodiments, the filling rate of the heat absorbing medium in the receiving hole is greater than 95%.

[0025] By adopting the technical solution of this embodiment, the heat absorbing medium occupies more than 95% of the total volume of the receiving hole, and the receiving hole is almost filled with the heat absorbing medium, thereby maximizing the heat absorbing capacity of the insulation layer and making the insulation pad have a good heat absorbing effect.

[0026] In some embodiments, the diameter of the receiving hole is 0.01 mm to 1 mm.

[0027] By adopting the technical solution of this embodiment, the aperture of the receiving hole is set within the aperture range mentioned above. For the solid heat absorbing medium, a smaller aperture can effectively confine it in the receiving hole. When the battery device is subjected to vibration, impact or temperature changes causing the material to expand and contract, the solid heat absorbing medium is not easy to escape from the aperture, so that the heat absorbing medium can be stably filled in the receiving hole, thereby providing a guarantee for the normal function of the thermal insulation pad.

[0028] In some embodiments, the sum of the cross-sectional areas of the receiving holes is less than or equal to one tenth of the surface area of ​​the thermal insulation layer.

[0029] By adopting the technical solution of this embodiment, while ensuring that the receiving holes can be filled with a sufficient amount of heat-absorbing medium, the sum of the cross-sectional areas of each receiving hole is controlled within a certain range, so as to ensure that the thermal insulation layer can still effectively block most of the heat transfer and ensure that the thermal insulation pad has stable thermal insulation performance.

[0030] In some embodiments, the thermal insulation layer is a composite material layer of fiber material and porous powder ceramic.

[0031] By adopting the technical solution of this embodiment, the fiber material usually has good flexibility and tensile strength, which can enhance the overall mechanical properties of the thermal insulation layer to a certain extent. At the same time, the interwoven structure of the fiber material can effectively block the conduction of heat. The efficiency of heat conduction along the fibers is relatively low, and the gaps between the fibers can also play a certain thermal insulation role. On this basis, porous powder ceramics are filled in the internal gaps of the fiber material, and the pores of the porous powder ceramics are filled with air, so that it has a lower thermal conductivity, thereby further improving the thermal insulation effect of the thermal insulation layer. In addition, the powder ceramics themselves have high high temperature resistance and can maintain structural stability at high temperatures, thereby reducing the risk of performance degradation or structural damage caused by deformation of the thermal insulation layer due to high temperature, which helps to improve the overall high temperature resistance of the thermal insulation pad and improve the thermal insulation effect.

[0032] In some embodiments, the fiber material includes one or more of pre-oxidized silk fiber felt, ceramic fiber felt, glass fiber felt, high silica fiber felt, basalt fiber felt, carbon fiber felt, spandex fiber felt, polyethylene terephthalate fiber felt, polyester fiber felt, and nylon fiber felt;

[0033] And / or, the porous powder ceramic includes one or more of silicon dioxide, zirconium oxide, and aluminum oxide.

[0034] In some embodiments, the porosity of the thermal insulation layer is 80% to 99%.

[0035] By adopting the technical solution of this embodiment, the thermal insulation layer has a larger porosity, so that there are more pores distributed inside the thermal insulation layer, and the pores are filled with air. When heat passes through the thermal insulation layer, it is necessary to continuously convert the conductive medium between the solid material and the gas in the pores, so that the resistance to heat transfer increases, and the thermal insulation layer has a good thermal insulation effect; in addition, the maximum porosity of the thermal insulation layer does not exceed 99%, so that the thermal insulation layer can maintain the structural integrity, and the solid structure part in the thermal insulation layer makes the thermal insulation layer itself have good strength, so that it can resist various stresses during use, thereby reducing the risk of collapse or deformation damage of the thermal insulation layer itself.

[0036] In some embodiments, the thermal conductivity of the thermal insulation layer at room temperature is less than 0.23 W / (m·K).

[0037] By adopting the technical solution of this embodiment, at room temperature, the thermal conductivity of the thermal insulation layer is controlled to be less than 0.23W / (m·K), that is, a material with a relatively low thermal conductivity is selected to make the thermal insulation layer, so that within the above temperature range, the thermal conductivity of the thermal insulation layer can be controlled to be below 0.23W / (m·K). In this way, the thermal conductivity of the thermal insulation layer is relatively small, the thermal resistance of the thermal insulation layer is large, and the heat transfer speed of the thermal insulation layer is slow, so that it is difficult for heat to pass through the thermal insulation layer, thereby slowing down heat transfer and improving the thermal insulation effect of the thermal insulation layer.

[0038] In some embodiments, the thickness of the thermal insulation layer is 1 mm to 10 mm.

[0039] By adopting the technical solution of this embodiment, the overall thickness of the insulation layer is 1mm~10mm, so that the insulation pad has a suitable size. Within this size range, the insulation pad can have sufficient insulation capacity to meet the insulation requirements, while not causing the insulation pad to be too thick and affecting the energy density of the battery device.

[0040] In some embodiments, the side edge of the first surface layer is sealingly connected to the side edge of the second surface layer to seal the thermal insulation layer.

[0041] By adopting the technical solution of this embodiment, the first surface layer and the second surface layer are sealed and connected at the peripheral position, the first surface layer and the second surface layer form a box-shaped structure, and the thermal insulation layer is encapsulated in the box-shaped structure formed by the first surface layer and the second surface layer, so that the first surface layer and the second surface layer can provide good protection for the thermal insulation layer, and at the same time, a certain amount of static air can be encapsulated in the first gap and the second gap to improve the overall thermal insulation effect of the thermal insulation pad.

[0042] In some embodiments, the first reflective layer is a mixed layer of a high temperature resistant resin and a heat reflective material, and / or the second reflective layer is a mixed layer of a high temperature resistant resin and a heat reflective material.

[0043] By adopting the technical solution of this embodiment, the high temperature resistant resin is an important component of the first reflective layer (second reflective layer), which provides basic structural support for the reflective layer, so that the first reflective layer (second reflective layer) can maintain structural integrity under high temperature conditions. At the same time, the high temperature resistant resin can also play a role in bonding the heat reflective material to ensure that the heat reflective material is evenly distributed in the reflective layer; and the heat reflective material has a high reflectivity to thermal radiation (such as infrared rays). After being mixed with the high temperature resistant resin, the first reflective layer can effectively reflect heat.

[0044] In some embodiments, the high temperature resistant resin includes one or more of polyimide resin, phenolic resin, silicone resin, epoxy resin, polybenzimidazole resin, and polyetheretherketone resin;

[0045] And / or, the heat reflective material includes one or more of carbon black, SiC powder, titanium dioxide, potassium hexatitanate whisker, zircon, ilmenite powder, and inorganic ceramic fiber.

[0046] In some embodiments, the thickness of the first reflective layer is 0.01 μm to 1.0 μm, and / or the thickness of the second reflective layer is 0.01 μm to 1.0 μm.

[0047] By adopting the technical solution of this embodiment, the thickness of the first reflective layer (second reflective layer) is designed within the above-mentioned range, so that the first reflective layer (second reflective layer) has a suitable size. Within this size range, the first reflective layer (second reflective layer) can have sufficient ability to reflect thermal radiation to meet the thermal insulation requirements, while at the same time not causing the thickness of the thermal insulation pad to be too thick, thereby affecting the energy density of the battery device.

[0048] In some embodiments, along the thickness direction of the thermal insulation pad, the size of the first gap is 0.5 μm to 1.0 μm, and / or the size of the second gap is 0.5 μm to 1.0 μm.

[0049] By adopting the technical solution of this embodiment, the first gap and the second gap have suitable sizes. Within this size range, the thermal insulation pad can have sufficient deformation space to meet the use requirements, while at the same time it will not cause the thermal insulation pad to be too thick and affect the energy density of the battery device.

[0050] In some embodiments, the thermal insulation pad further includes a first separator disposed between the first surface layer and the first reflective layer, the first separator is located on at least two opposite sides of the thermal insulation pad, and the first surface layer, the first separator and the first reflective layer are surrounded to form a first gap;

[0051] The thermal insulation pad also includes a second separator arranged between the second surface layer and the second reflective layer. The second separator is located on at least two opposite sides of the thermal insulation pad. The second surface layer, the second separator and the second reflective layer are arranged to form a second gap.

[0052] By adopting the technical solution of this embodiment, a first partition is set between the first surface layer and the first reflecting layer, and the space among the first surface layer, the first partition and the first reflecting layer is the first gap. At the same time, a second partition is set between the second surface layer and the thermal insulation pad, and the space among the second surface layer, the second partition and the second reflecting layer is the second gap. In this way, the overall structure of the thermal insulation pad is simple and easy to shape and produce.

[0053] In some embodiments, the first partition and the second partition are both elastic members.

[0054] By adopting the technical solution of this embodiment, the first partition is set as an elastic member, and the first partition has a certain deformation ability, so that it can also buffer the force exerted on the thermal insulation pad, which is beneficial to improving the buffering effect of the thermal insulation pad on the force and improving the deformation resistance of the thermal insulation pad.

[0055] In some embodiments, the thickness of the first surface layer is 0.01 μm to 0.1 μm, and / or the thickness of the second surface layer is 0.01 μm to 0.1 μm.

[0056] By adopting the technical solution of this embodiment, the thickness of the first surface layer (second surface layer) is controlled within the above-mentioned range, so that the first surface layer (second surface layer) has a suitable size. Within this size range, the first surface layer (second surface layer) can provide good protection for the intermediate thermal insulation layer and the first reflecting layer and the second reflecting layer, so that the thermal insulation pad can have good structural strength and structural stability. At the same time, the first gap and the second gap will not be too small in size, or the thickness of the thermal insulation layer will not be too small due to the excessive thickness of the first surface layer (second surface layer), thereby providing a guarantee for the thermal insulation effect of the thermal insulation pad.

[0057] In some embodiments, both the first surface layer and the second surface layer are insulating layers.

[0058] By adopting the technical solution of this embodiment, the first surface layer and the second surface layer are both set as insulating layers, so that the thermal insulation pad can be insulated, thereby reducing the risk of short circuit inside the battery device and providing protection for the normal use of the battery device.

[0059] In a second aspect, an electrical device is provided, comprising the above-mentioned battery device.

[0060] Since the electric device of the embodiment of the present application includes the above-mentioned battery device, it at least includes all the beneficial effects of the above-mentioned battery device, which will not be described in detail here.

[0061] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0063] Figure 1A schematic diagram of the structure of a vehicle provided in one embodiment of the present application;

[0064] Figure 2 A schematic diagram of the structure of a battery device provided in one embodiment of the present application;

[0065] Figure 3 for Figure 2 A schematic diagram of a partial structure of a battery device shown;

[0066] Figure 4 A cross-sectional view of a thermal insulation pad of a battery device provided in one embodiment of the present application;

[0067] Figure 5 A schematic diagram of the structure of a thermal insulation pad for a battery device provided in one embodiment of the present application;

[0068] Figure 6 A schematic structural diagram of a thermal insulation pad for a battery device provided in another embodiment of the present application;

[0069] Figure 7 for Figure 5 An exploded view of the thermal pad shown;

[0070] Figure 8 A schematic diagram of the structure of an experimental device for a thermal diffusion experiment provided in an embodiment of the present application;

[0071] Fig. 9 Thermogravimetric curve obtained when conducting a thermal insulation effect test experiment on the thermal insulation pad of the battery device provided in Example 1;

[0072] Fig.10 The cold surface temperature curve of the thermal insulation pad obtained when the thermal insulation effect test experiment is performed on the thermal insulation pad of the battery device provided in Example 1;

[0073] Fig.11 Thermogravimetric curve obtained when conducting a thermal insulation effect test experiment on the thermal insulation pad of the battery device provided in Example 2;

[0074] Fig.12 This is a cold surface temperature curve of the thermal insulation pad obtained when conducting a thermal insulation effect test experiment on the thermal insulation pad of the battery device provided in Example 2.

[0075] Among them, the reference numerals in the figure are:

[0076] 1. Battery device; 2. Controller; 3. Motor;

[0077] 10. Battery cells;

[0078] 20. Box body; 201. Accommodation space; 21. First part; 22. Second part;

[0079] 30, thermal insulation pad; 31, first surface layer; 32, second surface layer; 33, thermal insulation layer; 301, first gap; 302, second gap; 34, receiving hole; 341, solid heat absorption medium; 35, first reflection layer; 36, second reflection layer; 37, first partition; 38, second partition;

[0080] 40. Experimental apparatus; 41. Fixture; 42. Pressure gauge; 43. Heating table; 44. Thermal insulation pad to be tested; 45. Aluminum block; 46. Wooden block. DETAILED DESCRIPTION

[0081] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer, the following Figures 1 to 12 The present application is further described in detail in the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0082] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0083] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0084] Reference to "embodiments" herein means that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least some embodiments of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments in any suitable manner.

[0085] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0086] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets). "Several" means one or more than one, unless otherwise clearly and specifically defined.

[0087] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0088] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0089] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or indirectly connected to the other component.

[0090] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0091] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0092] Battery temperature is the most important parameter affecting battery performance and is currently the focus of research in the battery design process.

[0093] In the related art, a battery cell is the smallest unit that makes up a battery. The fundamental reason for battery overheating and instability is thermal runaway of the battery cells inside the battery. When the internal temperature of one or several battery cells exceeds a certain threshold, a series of uncontrollable chemical reactions will occur in the electrode assembly inside the battery cell, causing a short circuit and electrolyte combustion inside the battery cell, which will cause the temperature of the battery cell to become higher and higher, and may cause the battery cell to catch fire. Since the multiple battery cells inside the battery are arranged in a matrix in close proximity, if one of the battery cells has thermal runaway, the heat generated will quickly radiate to the surrounding area and be transmitted to the surrounding battery cells, causing the surrounding battery cells to be thermally baked and the temperature to continue to rise. Once heated to a temperature higher than the threshold, it will then cause thermal runaway of the surrounding battery cells. In this way, enhancing the heat isolation between the thermal runaway battery cell and the surrounding battery cells becomes one of the important means to prevent the spread of thermal runaway.

[0094] In this way, a heat insulation structure is set between adjacent battery cells, and the heat insulation structure forms a heat insulation barrier between adjacent battery cells, which can effectively delay heat diffusion. However, the heat insulation structure usually only has a heat insulation function. When a battery cell overheats or thermal runaway occurs, a large amount of heat will be generated rapidly in a short period of time. The heat insulation structure can delay heat diffusion, but it cannot effectively absorb or utilize the heat. The heat will eventually spread and affect other surrounding structures.

[0095] Based on this, an embodiment of the present application provides a battery device, wherein a thermal insulation pad is arranged between adjacent battery cells, the thermal insulation pad comprising a first surface layer, a second surface layer and a thermal insulation layer, the thermal insulation layer is arranged between the two surface layers, and a receiving hole is provided at least in the middle position of the thermal insulation layer, the receiving hole is filled with a heat absorption medium, the heat absorption medium can absorb heat, and when a battery cell has thermal runaway, at least part of the heat generated by it can be absorbed by the heat absorption medium in the thermal insulation pad, thereby effectively reducing the heat conducted to the adjacent battery cell, so that the thermal insulation pad can not only prolong the heat transfer time between adjacent battery cells and delay the occurrence speed of thermal runaway of adjacent battery cells, but also reduce the risk of thermal runaway of adjacent battery cells by absorbing heat. The thermal insulation pad has good thermal insulation effect and a certain heat absorption effect, and can effectively insulate the battery cells adjacent to it, so that the thermal stability of the battery device is improved and the reliability of use is improved.

[0096] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0097] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0098] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0099] For the convenience of description, an electric device is provided in accordance with an embodiment of the present application, and the electric device is described by taking a vehicle as an example.

[0100] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. The vehicle may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device is provided inside the vehicle, and the battery device may be provided at the bottom, head or tail of the vehicle. The battery device may be used to power the vehicle, for example, the battery device may be used as an operating power source for the vehicle. The vehicle may also include a controller and a motor, and the controller is used to control the battery device to power the motor, for example, for starting, navigating and driving the vehicle.

[0101] In some embodiments, the battery device can be used not only as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0102] Please also read Figure 2 The embodiment of the present application also provides a battery apparatus 1 (Battery Apparatus). The battery apparatus 1 may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly (Battery Cell Assembly) may include a plurality of battery cells 10, and the plurality of battery cells 10 are connected in series, in parallel, or in mixed connection through a busbar component.

[0103] In some embodiments, the battery device 1 includes a battery management system (BMS), which is a core component responsible for monitoring and managing the status of the battery cells 10. Its main functions include: real-time monitoring of the voltage, current, temperature and other parameters of the battery cells 10 to ensure that the battery is in a safe working state; balancing the power of each battery cell 10 in the battery cell assembly by active or passive means to extend the battery life; controlling and adjusting the temperature of the battery cell 10 to avoid performance degradation or safety risks caused by overheating or overcooling; detecting faults of the battery cell assembly and the BMS itself, and taking corresponding protection measures, such as cutting off the power supply and alarming.

[0104] As an example, the battery management system may be disposed in the box 20 , so that the box 20 supports and protects the battery management system.

[0105] As an example, the battery management system may also be disposed outside the housing 20 and connected to the battery cells 10 , sensors and other devices within the housing 20 through wires.

[0106] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells 10 .

[0107] As an example, the battery cell assembly may be a battery module (Battery Module), and the battery module is formed by arranging and fixing a plurality of battery cells 10 to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells 10 by a cable tie.

[0108] In some embodiments, the battery device 1 may be a battery pack, which includes a box 20 and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the box 20 .

[0109] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body 20 by fixing the battery module in the box body 20 .

[0110] As an example, the battery cell assembly may also be accommodated in the case 20 by directly fixing the plurality of battery cells 10 to the case 20 .

[0111] In some embodiments, the box 20 has a receiving space 201 inside to accommodate the battery cell 10. The box 20 can be made of a material with a certain hardness and strength, so that the box 20 is not easily deformed when squeezed or collided, so that the battery can have a higher structural strength and the reliability can also be improved. The box 20 can be made of a variety of materials, including but not limited to aluminum, stainless steel, aluminum alloy, iron or plastic.

[0112] In some embodiments, the box 20 can be used as a part of the chassis structure of the vehicle. For example, part of the box 20 can become at least a part of the floor of the vehicle, or part of the box 20 can become at least a part of the cross beam and longitudinal beam of the vehicle 100.

[0113] As an example, the box body 20 may include a first part 21 and a second part 22, and the first part 21 and the second part 22 cover each other so that a closed accommodation space 201 is formed inside the box body 20 to accommodate the battery cell assembly. The closed here means to cover or close, which can be sealed or unsealed. The first part 21 or the second part 22 can be the top cover or the bottom plate of the box body 20. The first part 21 and the second part 22 can also be hollow structures with one side open, and the open side of the first part 21 covers the open side of the second part 22.

[0114] As an example, the box body 20 may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed accommodation space 201 is formed inside the box body 20 to accommodate the battery monomer assembly.

[0115] In some embodiments, the battery cell 10 includes an electrode assembly and a housing, the electrode assembly is mounted in the housing to protect the electrode assembly through the housing, and one or more electrode assemblies may be contained in the housing.

[0116] The electrode assembly consists of a positive electrode sheet, a negative electrode sheet and a separator. The electrode assembly mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The part of the positive current collector that is not coated with the positive active material layer protrudes from the part that is coated with the positive active material layer. The part that is not coated with the positive active material layer serves as a positive electrode tab, or a metal conductor is welded on the positive current collector and led out to serve as a positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The portion of the negative electrode current collector not coated with the negative electrode active material layer protrudes from the portion coated with the negative electrode active material layer. The portion not coated with the negative electrode active material layer serves as a negative electrode tab, or a metal conductor is welded on the negative electrode current collector and led out to serve as a negative electrode tab. The negative electrode current collector may be made of copper, and the negative electrode active material may be carbon or silicon, etc.

[0117] The outer shell of the battery cell 10 is provided with an electrode terminal. The electrode terminal refers to a conductive part provided on the outer shell, and the electrode terminal is connected to the electrode tab of the electrode assembly to output the electric energy of the battery cell 10 or charge the battery cell 10. The battery cell 10 generally has two electrode terminals, which are respectively connected to the positive and negative electrode tabs of the electrode assembly. The electrode terminal connected to the positive electrode tab is the positive electrode terminal, and the electrode terminal connected to the negative electrode tab is the negative electrode terminal.

[0118] When the battery cell 10 is charged, the current converts electrical energy into chemical energy through the chemical reaction between the electrolyte and the electrode and stores it in the battery cell 10, while during the discharge process, the chemical energy is converted into electrical energy and released. This energy conversion process is accompanied by energy loss and heat generation. If the heat dissipation inside the battery cell 10 is poor and the heat cannot be effectively dissipated, the battery cell 10 will overheat. In addition, there is a certain internal resistance inside the battery cell 10, and resistance loss will be generated when the current passes through the internal resistance, causing the battery cell 10 to heat up. When the current is too large or the internal resistance is too high, the heat inside the battery cell 10 will intensify, causing the battery cell 10 to overheat. If the battery cell 10 exceeds its designed maximum voltage during charging, or the battery cell 10 voltage drops too low during discharge, it will cause the battery cell 10 to be overcharged or over-discharged. Overcharging or over-discharging will also cause the chemical reaction inside the battery cell 10 to get out of control, generate excessive heat, and cause the battery cell 10 to overheat.

[0119] Below, combined with the attached Figures 2 to 12 The battery device 1 of the present application is described in detail with reference to the specific embodiments.

[0120] In the embodiments of the present application, Figures 2 to 5 As shown, the battery device 1 includes a plurality of battery cells 10 and a thermal insulation pad 30; the thermal insulation pad 30 is arranged between two adjacent battery cells 10; the thermal insulation pad 30 includes a first surface layer 31, a second surface layer 32, and a thermal insulation layer 33 arranged between the first surface layer 31 and the second surface layer 32, and a plurality of accommodating holes 34 are arranged at least in the middle position of the thermal insulation layer 33, and the accommodating holes 34 are filled with a heat absorbing medium.

[0121] In this embodiment, the battery device 1 includes a plurality of battery cells 10, that is, the battery device 1 includes two or more battery cells 10. The plurality of battery cells 10 are arranged in sequence in a certain order. For example, the plurality of battery cells 10 may be arranged in sequence in one direction or in two mutually perpendicular directions. The battery cells 10 may be prismatic battery cells or cylindrical battery cells, such as square battery cells or hexagonal battery cells.

[0122] The battery device 1 also includes a thermal insulation pad 30, wherein the thermal insulation pad 30 is a structure for isolating heat, and the thermal insulation pad 30 is located between two adjacent battery cells 10, that is, a thermal insulation pad 30 is provided between the side of one battery cell 10 and the side of another battery cell 10, and the thermal insulation pad 30 is used to spatially separate adjacent battery cells 10, and the thermal insulation pad 30 can delay or reduce heat conduction between adjacent battery cells 10, thereby reducing the risk of adjacent battery cells 10 affecting each other due to heat conduction, for example, reducing the risk of overheating of one battery cell 10 and affecting the normal working state of the adjacent battery cell 10.

[0123] In the embodiment of the present application, the thermal insulation pad 30 is a multilayer structure, which includes a first surface layer 31, a second surface layer 32 and a thermal insulation layer 33. In a thermal insulation pad 30, the first surface layer 31 and the second surface layer 32 are the parts of the thermal insulation pad 30 facing the battery cell 10, which can be in direct contact with the battery cell 10, or can be spaced apart from the adjacent battery cell 10; the thermal insulation pad 30 is located between the first surface layer 31 and the second surface layer 32, and the first surface layer 31 and the second surface layer 32 can play a role in protecting the thermal insulation layer 33. The thermal insulation layer 33 is a key part for realizing the thermal insulation function. The thermal insulation layer 33 can have a structure with thermal insulation capacity, which can prevent the transfer of heat between adjacent battery cells 10 to a certain extent, thereby prolonging the heat transfer time. For example, the thermal insulation layer 33 can be made of thermal insulation material. For example, the thermal insulation material can be a single material such as glass fiber material, polysilicon material, nano silicon material, nano carbon fiber material, aerogel material, etc., or the thermal insulation material can also be a mixed material of multiple materials with thermal insulation function.

[0124] In the embodiment of the present application, a plurality of receiving holes 34 are further provided at least in the middle of the heat insulating layer 33, wherein the middle of the heat insulating layer 33 refers to the middle area of ​​the heat insulating layer 33 after removing the edge portions close to the first surface layer 31 and the second surface layer 32. For example, if the heat insulating layer 33 is rectangular, the middle of the heat insulating layer 33 can be understood as the inner area after removing a circle close to the four sides; or, if the heat insulating layer 33 is circular, the middle of the heat insulating layer 33 can be understood as the inner area after removing a circle close to the circular edge.

[0125] A plurality of accommodating holes 34 are provided at least in the middle of the thermal insulation pad 30. In some examples, one or more accommodating holes 34 are provided in the middle of the thermal insulation pad 30. In other examples, a plurality of accommodating holes 34 are dispersedly provided at various positions of the thermal insulation pad 30, and the positions are not limited to the middle of the thermal insulation pad 30.

[0126] The receiving hole 34 is filled with a heat absorbing material, and the receiving hole 34 provides storage space for the heat absorbing medium. The heat absorbing medium is filled in the receiving hole 34 and then forms a whole with the thermal insulation layer 33. When the battery cell 10 generates heat and conducts it to the thermal insulation layer 33, the heat absorbing medium in the receiving hole 34 can absorb the heat. For example, the heat absorbing medium has a high specific heat capacity and can increase its own temperature in the process of absorbing heat, but will not quickly continue to transfer the heat, so that the thermal insulation pad 30 has a certain ability to absorb heat. Exemplarily, the heat absorbing medium can be a poor conductor of heat such as air, or the heat absorbing medium can also be a phase change material. After absorbing heat, the phase change material will undergo a phase change, such as from solid to liquid or from solid to gas, and the phase change process can absorb heat.

[0127] The battery device 1 of the embodiment of the present application has a heat insulation pad 30 disposed between adjacent battery cells 10. The heat insulation pad 30 includes a first surface layer 31, a second surface layer 32 and a heat insulation layer 33. The heat insulation layer 33 is disposed between the two surface layers, and a receiving hole 34 is provided at least in the middle of the heat insulation layer 33. The receiving hole 34 is filled with a heat absorbing medium. The heat absorbing medium can absorb heat. When a battery cell 10 has thermal runaway, at least part of the heat generated by it can be absorbed by the heat absorbing medium in the heat insulation pad 30, thereby effectively reducing the heat conducted to the adjacent battery cells 10. The heat of the battery cell 10, so that the thermal insulation pad 30 can not only prolong the heat transfer time between adjacent battery cells 10, delay the occurrence speed of thermal runaway of adjacent battery cells 10, but also reduce the heat conduction by absorbing heat, thereby reducing the risk of thermal runaway of adjacent battery cells 10. The thermal insulation pad 30 has good thermal insulation effect and certain heat absorption effect, and can effectively insulate the battery cells 10 adjacent to it, so that the thermal stability of the battery device 1 is improved, and the reliability of use is improved.

[0128] In the embodiments of the present application, Figure 4 and Figure 7 As shown, the thermal insulation pad 30 further includes a first reflective layer 35 and a second reflective layer 36 . The first reflective layer 35 covers the surface of the thermal insulation layer 33 facing the first surface layer 31 , and the second reflective layer 36 covers the surface of the thermal insulation layer 33 facing the second surface layer 32 .

[0129] In this embodiment, the thermal insulation pad 30 also has a first reflective layer 35 and a second reflective layer 36. The first reflective layer 35 covers the surface of the thermal insulation layer 33 facing the first surface layer 31, and the second reflective layer 36 covers the surface of the thermal insulation layer 33 facing the second surface layer 32. The reflective layer can be tightly combined with the thermal insulation layer 33. When heat is conducted from the battery cell 10, according to the direction of the heat source, the heat will first contact the first reflective layer 35 or the second reflective layer 36, and then reach the thermal insulation layer 33. Exemplarily, the first reflective layer 35 and the second reflective layer 36 can be coated on the surface of the thermal insulation layer 33 by scraping or the like.

[0130] In this way, by covering the first reflective layer 35 and the second reflective layer 36 on the two side surfaces of the thermal insulation layer 33, the first reflective layer 35 and the second reflective layer 36 cooperate with other parts of the thermal insulation pad 30 (the first surface layer 31, the second surface layer 32 and the thermal insulation layer 33) to form a multi-level thermal insulation system. The first surface layer 31 and the second surface layer 32 may play a role of protection and preliminary isolation, and the first reflective layer 35 and the second reflective layer 36 are mainly used to reflect heat, thereby reducing the heat transferred by thermal radiation and reducing the transfer of heat to the thermal insulation layer 33. The thermal insulation layer 33 further prevents the conduction of heat, thereby further enhancing the thermal insulation performance of the thermal insulation pad 30.

[0131] In the embodiments of the present application, Figure 4 , Figure 5 and Figure 7 As shown, a first gap 301 is provided between the first reflective layer 35 and the first surface layer 31 , and a second gap 302 is provided between the second reflective layer 36 and the second surface layer 32 .

[0132] In the embodiment of the present application, the thermal insulation pad 30 also has a first gap 301 and a second gap 302, wherein the first surface layer 31 and the first reflective layer 35 are spaced apart to form the first gap 301 therebetween, and the second surface layer 32 and the second reflective layer 36 are spaced apart to form the second gap 302 therebetween. By setting the first gap 301 and the second gap 302, on the one hand, the first gap 301 and the second gap 302 can play a buffering role. When the battery device 1 is subjected to external impact or the battery cell 10 expands and deforms, the first gap 301 and the second gap 302 can effectively buffer the external force, thereby reducing the risk of the thermal insulation pad 30 being damaged by extrusion. Specifically, when the battery cell 10 expands and extrudes the thermal insulation pad 30, due to the existence of the first gap 301 and the second gap 302, the middle part of the thermal insulation pad 30 has a larger deformation space, and the middle part of the thermal insulation pad 30 can withstand a greater extrusion force to adapt to the larger expansion and deformation that may occur in the middle area of ​​the battery cell 10; on the other hand, the first gap 301 and the second gap 302 can be filled with air, and air is a poor conductor of heat. In this way, the thermal insulation effect of the thermal insulation pad 30 can be enhanced to a certain extent.

[0133] In some embodiments, Figure 4 , Figure 5 and Figure 7 As shown, at least one side surface of the thermal insulation layer 33 is provided with an opening, and along the thickness direction of the thermal insulation pad 30, the receiving hole 34 is connected to the opening.

[0134] It can be understood that at least one side surface of the thermal insulation layer 33 is provided with an opening, which means that the side surface of the thermal insulation layer 33 facing the first surface layer 31 is provided with an opening, or the side surface of the thermal insulation layer 33 facing the second surface layer 32 is provided with an opening, or both the side surface of the thermal insulation layer 33 facing the first surface layer 31 and the side surface of the thermal insulation layer 33 facing the second surface layer 32 are provided with openings. The accommodating hole 34 is connected to the opening, that is, when an opening is provided on the side surface of the thermal insulation layer 33 facing the first surface layer 31, the accommodating hole 34 is connected to the opening provided on the side surface of the thermal insulation layer 33 facing the first surface layer 31; or, when an opening is provided on the side surface of the thermal insulation layer 33 facing the second surface layer 32, the accommodating hole 34 is connected to the opening provided on the side surface of the thermal insulation layer 33 facing the second surface layer 32; or, when openings are provided on the side surface of the thermal insulation layer 33 facing the first surface layer 31 and the side surface of the thermal insulation layer 33 facing the second surface layer 32, the accommodating hole 34 is simultaneously connected to the openings provided on the two opposite surfaces of the thermal insulation layer 33, that is, along the thickness direction of the thermal insulation pad 30, the accommodating hole 34 passes through the thermal insulation layer 33, that is, the accommodating hole 34 is not completely enclosed inside the thermal insulation layer 33.

[0135] In this way, when the battery cell 10 generates heat and conducts it to the surface of the thermal insulation layer 33 close to the battery cell 10, by setting the receiving hole 34 to penetrate this side surface, the heat can be more directly transferred to the heat-absorbing medium in the receiving hole 34, so that the heat-absorbing medium can absorb heat in time, further improving the thermal insulation effect of the thermal insulation pad 30.

[0136] It should be noted that, in this embodiment, when the first surface layer 31 or the second surface layer 32 is provided with an opening, the first reflective layer 35 and the second reflective layer 36 cover the corresponding opening, that is, the accommodating hole 34 is first provided on the heat insulating layer 33, and after the heat absorbing medium is filled in the accommodating hole 34, the first reflective layer 35 and the second reflective layer 36 are coated on the surface of the heat insulating layer 33. That is, the accommodating hole 34 is sandwiched between the first reflective layer 35 and the second reflective layer 36.

[0137] In some embodiments, Figure 4 , Figure 5 and Figure 7 As shown, there are multiple accommodating holes 34 , and the multiple accommodating holes 34 are evenly distributed in the middle of the thermal insulation layer 33 .

[0138] A plurality of accommodating holes 34 are evenly arranged in the middle of the thermal insulation pad 30 , and the plurality of accommodating holes 34 are symmetrically distributed around the center of the thermal insulation layer 33 , so that the heat absorbing medium can be evenly distributed in the middle area of ​​the thermal insulation layer 33 , thereby further improving the heat absorption capacity.

[0139] In some embodiments, Figure 4 , Figure 5 and Figure 7 Therefore, the heat absorbing medium includes a solid heat absorbing medium 341, and the solid heat absorbing medium 341 is at least partially decomposed into gas by heat when the temperature reaches a threshold value.

[0140] When the temperature reaches a threshold, at least part of the solid heat absorbing medium 341 is thermally decomposed into gas, which means that when the temperature exceeds a certain threshold, part or all of the solid heat absorbing medium 341 can be thermally decomposed, and the main product of the thermal decomposition is gas, wherein the threshold refers to the critical temperature when the solid heat absorbing medium 341 is thermally decomposed. When the temperature exceeds this threshold, the molecular structure of the solid heat absorbing medium 341 begins to change, breaking the original chemical bonds, thereby generating gas. Exemplarily, the threshold can be any value in the range of 150°C to 350°C, so that the heat absorbing medium can undergo a thermal decomposition reaction at a faster speed, thereby accelerating the speed of further absorbing heat.

[0141] In this way, the solid heat absorption medium 341 is filled in the receiving hole 34 of the insulation layer 33. At normal temperature, the heat absorption medium exists in a solid form, so that it can be stably filled in the receiving hole 34 without being unevenly distributed or flowing out of the receiving hole 34 due to easy flow. When the temperature exceeds a certain threshold, the solid heat absorption medium 341 is thermally decomposed, thereby absorbing heat faster. After absorbing heat, the medium directly generates gas from the solid state without or only a small amount of liquid, thereby helping to reduce the risk of short circuit inside the battery device due to the outflow of thermal decomposition products from the insulation pad.

[0142] In some embodiments, the heat absorbing medium includes one or more of carbonate, bicarbonate, phosphate, and hydrogen phosphate.

[0143] In this way, one or more of the above materials are used as heat absorbing media to fill the receiving hole 34, which decomposes to produce gas when heated. Moreover, when the heat absorbing medium is a mixture of the above substances, since the decomposition temperatures of different substances may be different, their combination can play a heat absorbing role in different temperature ranges and expand the temperature control range. In addition, different gases have different thermal conductivities and obstacles to heat transfer. Through reasonable matching, the gas composition in the receiving hole 34 can be made more complex, further reducing the thermal conductivity and enhancing the thermal insulation effect.

[0144] In some embodiments, the heat absorbing medium also includes an adhesive, which is mixed with one or more of the above-mentioned carbonates, bicarbonates, phosphates, and hydrogen phosphates, so that the heat absorbing medium can be stably bonded to the receiving hole 34, thereby filling the receiving hole 34.

[0145] In a specific embodiment, the adhesive may be, but is not limited to, water glass, silica sol, ethyl silicate, polyvinylidene fluoride, polyacrylic acid, polyvinyl pyrrolidone, etc. The adhesive accounts for about 10% of the total volume of the heat absorbing medium, that is, the ratio of the adhesive to the functional heat absorbing substances such as carbonate, bicarbonate, phosphate, and hydrogen phosphate in the unit volume of the heat absorbing medium is about 9:1. In this way, the use requirements of the heat absorbing medium for bonding and filling the receiving hole 34 are met, and the heat absorption effect of the heat absorbing medium will not be affected due to the excessive proportion of the adhesive.

[0146] In some embodiments, the filling rate of the heat absorbing medium in the receiving hole 34 is greater than 95%.

[0147] The filling rate of the heat absorbing medium in the receiving hole 34 refers to the volume ratio of the heat absorbing medium in the receiving hole 34. For example, when the volume of the receiving hole 34 is 100 cubic millimeters, the volume of the heat absorbing medium is at least 95 cubic millimeters.

[0148] In this embodiment, the heat absorbing medium occupies more than 95% of the total volume of the accommodating hole 34, and the accommodating hole 34 is almost filled with the heat absorbing medium, thereby maximizing the heat absorbing capacity of the thermal insulation layer 33 and making the thermal insulation pad 30 have a good heat absorbing effect.

[0149] In some embodiments, Figure 4 , Figure 5 and Figure 7 As shown, the diameter of the receiving hole 34 is 0.01 mm to 1 mm.

[0150] In this way, the aperture of the receiving hole 34 is set within the aperture range mentioned above. For the solid heat absorption medium 341, a smaller aperture can effectively confine it in the receiving hole 34. When the battery device 1 is subjected to vibration, impact or temperature changes causing the material to expand and contract, the solid heat absorption medium 341 is not easy to escape from the hole, so that the heat absorption medium can be stably filled in the receiving hole 34, thereby providing a guarantee for the normal function of the thermal insulation pad 30.

[0151] In a specific embodiment, the aperture of the receiving hole 34 can be 0.01mm, 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm, etc. The specific size of the aperture of the receiving hole 34 is not limited here, and it can be designed according to the requirements.

[0152] In some embodiments, the sum of the cross-sectional areas of the receiving holes 34 is less than or equal to one tenth of the surface area of ​​the thermal insulation layer 33 .

[0153] That is, the sum of the cross-sectional areas of the receiving holes 34 does not exceed one tenth of the total surface area of ​​the thermal insulation layer 33. While ensuring that the receiving holes 34 can be filled with a sufficient amount of heat-absorbing medium, the sum of the cross-sectional areas of each receiving hole 34 is controlled within a certain range to ensure that the thermal insulation layer 33 can still effectively block most of the heat transfer and ensure that the thermal insulation pad 30 has stable thermal insulation performance.

[0154] Among them, the cross-sectional area of ​​the accommodating hole 34 refers to the area of ​​the cross section of the accommodating hole 34 perpendicular to the thickness direction of the thermal insulation pad 30 , and the surface area of ​​the thermal insulation layer 33 refers to the area of ​​the surface of the thermal insulation layer 33 perpendicular to the thickness direction of the thermal insulation pad 30 .

[0155] In some embodiments, the thermal insulation layer 33 is a composite material layer of fiber material and porous powder ceramic.

[0156] It can be understood that fiber materials usually have good flexibility and tensile strength, which can enhance the overall mechanical properties of the insulation layer 33 to a certain extent. At the same time, the interwoven structure of the fiber material can effectively block the conduction of heat. The efficiency of heat conduction along the fibers is relatively low, and the gaps between the fibers can also play a certain role in insulation. On this basis, porous powder ceramics are filled in the internal gaps of the fiber material, and the pores of the porous powder ceramics are filled with air, so that it has a lower thermal conductivity, thereby further improving the insulation effect of the insulation layer 33. In addition, the powder ceramics themselves have high high temperature resistance and can maintain structural stability at high temperatures, thereby reducing the risk of deformation of the insulation layer 33 due to high temperature, resulting in performance degradation or structural damage, which helps to improve the overall high temperature resistance of the insulation pad 30 and improve the insulation effect.

[0157] In some embodiments, the fiber material can be any one or more combinations of pre-oxidized silk fiber felt, ceramic fiber felt, glass fiber felt, high silica fiber felt, basalt fiber felt, carbon fiber felt, spandex fiber felt, polyethylene terephthalate (PET) fiber felt, polyester fiber felt, nylon fiber felt or other fiber felts with flame retardant function.

[0158] In some embodiments, the porous powder ceramic can be any one or more combinations of materials such as silicon dioxide, zirconium oxide, and aluminum oxide.

[0159] In some embodiments, the porosity of the thermal insulation layer 33 is 80% to 99%.

[0160] The porosity of the thermal insulation layer 33 refers to the percentage of the volume of the internal pores of the thermal insulation layer 33 to the total volume of the thermal insulation layer 33. For the thermal insulation layer 33, the porosity is 80% to 99%, indicating that most of the internal space of the thermal insulation layer 33 is pores, that is, the thermal insulation layer 33 has a large porosity, so that there are more pores distributed inside the thermal insulation layer 33, and the pores are filled with air. When heat passes through the thermal insulation layer 33, it is necessary to continuously convert the conductive medium between the solid material and the gas in the pores, so that the resistance to heat transfer increases, and the thermal insulation layer 33 has a good thermal insulation effect. In addition, the maximum porosity of the thermal insulation layer 33 does not exceed 99%, so that the thermal insulation layer 33 can maintain the integrity of the structure. The solid structure part in the thermal insulation layer 33 makes the thermal insulation layer 33 itself have good strength, so that it can resist various stresses during use, thereby reducing the risk of collapse or deformation damage of the thermal insulation layer 33 itself.

[0161] In a specific embodiment, the porosity of the thermal insulation layer 33 can be 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98% or 99%, etc. There is no unique limitation on it here, and it can be selected according to specific usage requirements during design.

[0162] In some embodiments, the thermal conductivity of the heat insulation layer 33 at room temperature is less than 0.23 W / (m·K)

[0163] In this embodiment, it should be noted that the thermal conductivity of the thermal insulation layer 33 is a physical quantity used to measure the ability of the thermal insulation layer 33 to conduct heat, and the thermal conductivity of the thermal insulation layer 33 varies depending on the material used for the thermal insulation layer 33. Generally, the smaller the thermal conductivity of the thermal insulation layer 33, the slower the heat transfer rate of the thermal insulation layer 33, and the greater the thermal resistance, which means that heat can pass through the thermal insulation layer 33 more slowly, so that it can better maintain the temperature. Therefore, when heat preservation is required or the speed of heat conduction in the material needs to be reduced, it is necessary to use a material with a small thermal conductivity to make the thermal insulation layer 33, so that it is difficult for heat to pass through the thermal insulation layer 33, thereby slowing down heat transfer and improving the thermal insulation effect.

[0164] The unit of thermal conductivity is usually Watt per meter per degree Kelvin (W / m·K). The thermal conductivity of the thermal insulation layer 33 can be measured by experiments, for example, by a steady-state hot plate method (such as ASTM D5470) or a transient plane heat source method (such as ISO 22007-2).

[0165] In this embodiment, at room temperature, that is, when the temperature is in the range of 15°C to 30°C, the thermal conductivity of the thermal insulation layer 33 is controlled to be less than 0.23W / (m·K), that is, a material with a relatively low thermal conductivity is selected to make the thermal insulation layer 33, so that when it is in the above temperature range, the thermal conductivity of the thermal insulation layer 33 can be controlled to be below 0.23W / (m·K). In this way, the thermal conductivity of the thermal insulation layer 33 is relatively small, the thermal resistance of the thermal insulation layer 33 is large, and the heat transfer speed of the thermal insulation layer 33 is slow, so that it is difficult for heat to pass through the thermal insulation layer 33, thereby slowing down heat transfer and improving the thermal insulation effect of the thermal insulation layer 33.

[0166] In a specific embodiment, at room temperature, the thermal conductivity of the thermal insulation layer 33 can be 0.05 (W / m·K), 0.08 (W / m·K), 0.1 (W / m·K), 0.12 (W / m·K), 0.15 (W / m·K), 0.18 (W / m·K), 0.2W / m·K), 0.22 (W / m·K) or 0.23W / (m·K), etc. This embodiment does not impose a single limitation on the thermal conductivity value of the thermal insulation layer 33, and the value can be selected as needed during design.

[0167] In some embodiments, Figure 4 and Figure 7 As shown, the thickness of the heat insulation layer 33 is 1 mm to 10 mm.

[0168] In this way, the overall thickness of the insulation layer 33 is 1mm~10mm, so that the insulation pad 30 has a suitable size. Within this size range, the insulation pad 30 can have sufficient insulation capacity to meet the insulation requirements, while at the same time not affecting the energy density of the battery device 1 due to the insulation pad 30 being too thick.

[0169] In a specific embodiment, the thickness of the insulation layer 33 can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc. The specific size of the thickness of the insulation layer 33 is not limited here, and it can be designed according to the needs.

[0170] In some embodiments, the side edge of the first surface layer 31 is sealed to the side edge of the second surface layer 32 to seal the thermal insulation layer 33 .

[0171] In this way, the first surface layer 31 and the second surface layer 32 are sealed and connected at the circumferential side positions, and the first surface layer 31 and the second surface layer 32 form a box-shaped structure. The thermal insulation layer 33 is encapsulated in the box-shaped structure formed by the first surface layer 31 and the second surface layer 32, so that the first surface layer 31 and the second surface layer 32 can provide good protection for the thermal insulation layer 33, and at the same time, can also reduce the risk of the decomposition products of the heat absorbing medium escaping from the thermal insulation pad 30.

[0172] Among them, the side edge of the first surface layer 31 is sealed to the side edge of the second surface layer 32. For example, a sealant can be applied between the first surface layer 31 and the second surface layer 32 for sealing, or heat sealing can be used for sealing, or a sealing structure such as a sealing ring can be set on the side edge of the first surface layer 31 and the side edge of the second surface layer 32 for sealing.

[0173] In some embodiments, the first reflective layer 35 is a mixed layer of high temperature resistant resin and heat reflective material.

[0174] It can be understood that the first reflective layer 35 includes a high temperature resistant resin, which is an important component of the first reflective layer 35. The high temperature resistant resin has the ability to maintain stable physical and chemical properties under high temperature environment. For example, some polyimide resins can work normally at high temperatures of 200°C to 300°C without softening or decomposition. The first reflective layer 35 also includes a heat reflective material, which is a key component that gives the first reflective layer 35 the function of reflecting heat. These materials have high reflectivity to thermal radiation (such as infrared rays). For example, common heat reflective materials include metal flakes (such as aluminum foil) or metal oxides (such as titanium dioxide), etc. Among them, metal flakes are good heat reflectors because the free electrons in the metal can effectively reflect thermal radiation. Taking aluminum foil as an example, its reflectivity to infrared rays can reach more than 90%; while metal oxides reflect thermal radiation through their special crystal structure and optical properties.

[0175] Thus, in this embodiment, the high temperature resistant resin provides basic structural support for the first reflective layer 35, so that the first reflective layer 35 can maintain structural integrity under high temperature conditions. At the same time, the high temperature resistant resin can also play a role in bonding the heat reflective material to ensure that the heat reflective material is evenly distributed in the reflective layer; and the heat reflective material has a high reflectivity to thermal radiation (such as infrared rays). After being mixed with the high temperature resistant resin, the first reflective layer 35 can effectively reflect heat. In this way, the first reflective layer 35 works in coordination with other parts of the thermal insulation pad 30 (such as the second reflective layer 36 and the thermal insulation layer 33, etc.). The first reflective layer 35 first reflects the heat, reducing the burden of the thermal insulation layer 33, and then the thermal insulation layer 33 further absorbs and prevents the conduction of the remaining heat, so that this multi-layer thermal insulation structure can more effectively control the heat transfer between the battery cells 10 and maintain the temperature stability of the battery device 1. At the same time, the first reflective layer 35 covers the surface of the thermal insulation layer 33 facing the first surface layer 31, and also provides a certain protection for the thermal insulation layer 33.

[0176] In some embodiments, the second reflective layer 36 is a mixed layer of high temperature resistant resin and heat reflective material.

[0177] It can be understood that the structure and composition of the second reflective layer 36 and the relevant functional characteristics of the heat reflective material are substantially similar to those of the first reflective layer 35 described above, and will not be described in detail herein.

[0178] In this embodiment, the high temperature resistant resin provides basic structural support for the second reflective layer 36, so that the second reflective layer 36 can maintain structural integrity under high temperature conditions. At the same time, the high temperature resistant resin can also play a role in bonding the heat reflective material to ensure that the heat reflective material is evenly distributed in the reflective layer; the heat reflective material has a high reflectivity to thermal radiation (such as infrared rays), and after being mixed with the high temperature resistant resin, the second reflective layer 36 can effectively reflect heat. In this way, the second reflective layer 36 works in coordination with other parts of the thermal insulation pad 30 (such as the first reflective layer 35 and the thermal insulation layer 33, etc.), and the second reflective layer 36 first reflects the heat to reduce the burden of the thermal insulation layer 33, and then the thermal insulation layer 33 further absorbs and prevents the conduction of the remaining heat, so that this multi-layer thermal insulation structure can more effectively control the heat transfer between the battery cells 10 and maintain the temperature stability of the battery device 1. At the same time, the second reflective layer 36 covers the surface of the thermal insulation layer 33 facing the second surface layer 32, and also provides a certain protection for the thermal insulation layer 33.

[0179] In a specific embodiment, the heat reflective material includes but is not limited to one or more of carbon black, SiC powder, titanium dioxide, potassium hexatitanate whiskers, zircon, ilmenite powder, inorganic ceramic fiber, etc., which can be selected according to actual needs during design.

[0180] In a specific embodiment, the high temperature resistant resin includes but is not limited to one or more of polyimide resin, phenolic resin, silicone resin, epoxy resin, polybenzimidazole resin, polyetheretherketone resin, etc., which can be selected according to actual needs during design.

[0181] In some embodiments, Figure 4 and Figure 7 As shown, the thickness of the first reflective layer 35 is 0.01 μm to 1.0 μm. The thickness of the first reflective layer 35 is designed within the above range, so that the first reflective layer 35 has a suitable size. Within this size range, the first reflective layer 35 can have sufficient ability to reflect thermal radiation to meet the thermal insulation requirements, while not causing the thickness of the thermal insulation pad 30 to be too thick, thereby affecting the energy density of the battery device 1.

[0182] In a specific embodiment, the thickness of the first reflective layer 35 can be 0.01μm, 0.05μm, 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm or 1μm, etc. The specific size of the thickness of the first reflective layer 35 is not limited here, and it can be designed according to the requirements.

[0183] In some embodiments, Figure 4 and Figure 7As shown, the thickness of the second reflective layer 36 is 0.01 μm to 1.0 μm. The thickness of the second reflective layer 36 is designed within the above range so that the second reflective layer 36 has a suitable size. Within this size range, the second reflective layer 36 can have sufficient ability to reflect thermal radiation to meet the heat insulation requirements, while not causing the thickness of the heat insulation pad 30 to be too thick, thereby affecting the energy density of the battery device 1.

[0184] In a specific embodiment, the thickness of the second reflective layer 36 can be 0.01μm, 0.05μm, 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm or 1μm, etc. The specific size of the thickness of the second reflective layer 36 is not limited here, and it can be designed according to the requirements.

[0185] It should be noted that along the thickness direction of the thermal insulation pad 30, the thickness of the first reflective layer 35 can be equal to the thickness of the second reflective layer 36, or the thickness of the first reflective layer 35 can be different from the thickness of the second reflective layer 36. Within the above-mentioned size range, it can be designed according to specific usage requirements.

[0186] In some embodiments, Figure 4 and Figure 7 As shown, along the thickness direction of the thermal insulation pad 30 , the size of the first gap 301 is 0.5 μm-1.0 μm.

[0187] It can be understood that the thickness direction of the thermal insulation pad 30 is the direction indicated by the double-headed arrow F1 in the figure. In actual use, this direction is the same as the width direction of the gap between two adjacent battery cells 10 .

[0188] In this way, the dimension L1 of the first gap 301 along the thickness direction of the thermal insulation pad 30 is set to 0.5μm~1.0μm, so that the first gap 301 has a suitable size. Within this size range, the thermal insulation pad 30 can have sufficient deformation space to meet the use requirements of buffering the expansion of the battery cell 10, while not causing the thermal insulation pad 30 to be too thick and affecting the energy density of the battery device 1.

[0189] In a specific embodiment, the size of the first gap 301 along the thickness direction of the thermal insulation pad 30 can be 0.5μm, 0.6μm, 0.7μm, 0.75μm, 0.8μm, 0.85μm, 0.9μm, 0.95μm or 1.0μm, etc. The specific size of the first gap 301 is not limited here and can be designed as needed during use.

[0190] In some embodiments, Figure 4 and Figure 7As shown, along the thickness direction of the thermal insulation pad 30 , the size of the second gap 302 is 0.5 μm-1.0 μm.

[0191] Similar to the first gap 301, the dimension L2 of the second gap 302 along the thickness direction of the thermal insulation pad 30 is set to 0.5μm~1.0μm, so that the second gap 302 has a suitable size. Within this size range, the thermal insulation pad 30 can have sufficient deformation space to meet the use requirements of the buffer battery cell 10 expansion, while not causing the thermal insulation pad 30 to be too thick and affecting the energy density of the battery device 1.

[0192] In a specific embodiment, the size of the second gap 302 along the thickness direction of the thermal insulation pad 30 can be 0.5μm, 0.6μm, 0.7μm, 0.75μm, 0.8μm, 0.85μm, 0.9μm, 0.95μm or 1.0μm, etc. The specific size of the first gap 301 is not limited here and can be designed as needed during use.

[0193] It should be noted that along the thickness direction of the thermal insulation pad 30, the size of the first gap 301 can be equal to the size of the second gap 302, or the size of the first gap 301 can be different from the size of the second gap 302. Within the above-mentioned size range, the design can be carried out according to specific usage requirements.

[0194] In some embodiments, Figures 4 to 7 As shown, the thermal insulation pad 30 also includes a first separator 37 disposed between the first surface layer 31 and the first reflective layer 35, the first separator 37 is located on at least two opposite sides of the thermal insulation pad 30, and the first surface layer 31, the first separator 37 and the first reflective layer 35 are arranged to form a first gap 301; the thermal insulation pad 30 also includes a second separator 38 disposed between the second surface layer 32 and the second reflective layer 36, the second separator 38 is located on at least two opposite sides of the thermal insulation pad 30, and the second surface layer 32, the second separator 38 and the second reflective layer 36 are arranged to form a second gap 302.

[0195] Among them, along the direction perpendicular to the thickness direction of the thermal insulation pad 30, the first separator 37 (the second separator 38) is located on at least two opposite sides of the thermal insulation pad 30, which means that the number of the first separators 37 (the second separators 38) can be two or more, and at least one of the two or more first separators 37 (the second separators 38) is arranged on one side of the thermal insulation pad 30, and the other is arranged on the other opposite side.

[0196] For example, Figures 5 to 7As shown, the number of first separators 37 (second separators 38) is two, one of which is arranged on one side of the thermal insulation pad 30 along the length direction, and the other first separator 37 (second separator 38) is arranged on the other opposite side of the thermal insulation pad 30 along the length direction; or, the number of first separators 37 (second separators 38) is four, two of which are respectively arranged on the opposite sides of the thermal insulation pad 30 along the length direction, and the other two first separators 37 (second separators 38) are respectively arranged on the opposite sides of the thermal insulation pad 30 along the width direction; or, the first separator 37 (second separator 38) can also be an annular member, and the first separator 37 (second separator 38) is arranged around the side of the thermal insulation pad 30, so that the side of the thermal insulation pad 30 has the first separator 37 (second separator 38), wherein the length direction and the width direction are both perpendicular and perpendicular to the thickness direction of the thermal insulation pad 30.

[0197] In this embodiment, a first separator 37 (a second separator 38) is provided on at least two opposite sides of the thermal insulation pad 30, that is, the first separator 37 (the second separator 38) is sandwiched between the corresponding first surface layer 31 (the second surface layer 32) and the first reflective layer 35 (the second reflective layer 36) at at least two opposite sides of the thermal insulation pad 30, and the first separator 37 (the second separator 38) cushions the first surface layer 31 (the second surface layer 32) and prevents it from contacting with the corresponding first reflective layer 35 (the second reflective layer 36). The first surface layer 31 (the second surface layer 32) and the first reflecting layer 35 (the second reflecting layer 36) are combined to form a first gap 301 (the second gap 302) between them. The size of the first gap 301 (the second gap 302) can be determined by designing the size of the first partition 37 (the second partition 38) along the thickness direction of the thermal insulation pad 30, that is, the thickness size of the first partition 37 (the second partition 38). The first gap 301 (the second gap 302) is easy to form, and the thermal insulation pad 30 is easy to process and mass produce.

[0198] In some embodiments, the first separator 37 and the second separator 38 are both elastic members. In this way, the first separator 37 and the second separator 38 are both set as elastic members, and the first separator 37 and the second separator 38 have a certain deformation ability, so that the force exerted on the thermal insulation pad 30 can be buffered, which is beneficial to improving the buffering effect of the thermal insulation pad 30 on the force and improving the anti-deformation ability of the thermal insulation pad 30.

[0199] In some embodiments, Figure 4 and Figure 7 As shown, along the thickness direction of the thermal insulation pad 30 , the thickness of the first separator 37 is 0.5 μm to 1.2 μm.

[0200] In this way, the thickness of the first separator 37 is designed within the above thickness range, so that the size of the first gap 301 can fall within the size interval of 0.5 μm to 1.0 μm, meeting the size molding requirements of the first gap 301 .

[0201] In a specific embodiment, the dimension of the first separator 37 along the thickness direction of the thermal insulation pad 30 can be 0.5μm, 0.6μm, 0.7μm, 0.75μm, 0.8μm, 0.85μm, 0.9μm, 0.95μm, 1.0μm, 1.1μm or 1.2μm, etc. The specific thickness dimension of the first separator 37 is not uniquely limited here, and it can be designed according to the size requirements of the first gap 301 during design.

[0202] In some embodiments, Figure 4 and Figure 7 As shown, along the thickness direction of the thermal insulation pad 30 , the thickness of the second separator 38 is 0.5 μm to 1.2 μm.

[0203] In this way, the thickness of the second separator 38 is designed within the above thickness range, so that the size of the second gap 302 can fall within the size interval of 0.5 μm to 1.0 μm, meeting the size molding requirements of the second gap 302 .

[0204] In a specific embodiment, the dimension of the second separator 38 along the thickness direction of the thermal insulation pad 30 can be 0.5μm, 0.6μm, 0.7μm, 0.75μm, 0.8μm, 0.85μm, 0.9μm, 0.95μm, 1.0μm, 1.1μm or 1.2μm, etc. The specific thickness dimension of the first separator 37 is not uniquely limited here, and the design can be based on the size requirements of the first gap 301.

[0205] It should be noted that, in a specific embodiment, along the thickness direction of the thermal insulation pad 30, the thickness of the first partition 37 may be the same as the thickness of the second partition 38, or the thickness of the first partition 37 may be different from the thickness of the second partition 38. Within the above-mentioned size range, the design can be carried out according to specific usage requirements.

[0206] In some embodiments, Figure 4 and Figure 7 As shown, the thickness of the first surface layer 31 is 0.01 μm-0.1 μm.

[0207] The thickness of the first surface layer 31 is controlled within the above range so that the first surface layer 31 has a suitable size. Within this size range, the first surface layer 31 can provide good protection for the internal thermal insulation layer 33, the first reflective layer 35 and the second reflective layer 36, so that the thermal insulation pad 30 has good structural strength and structural stability. At the same time, the first gap 301 and the second gap 302 will not be too small in size, or the thickness of the thermal insulation layer 33 will not be too small due to the excessive thickness of the first surface layer 31, thereby providing a guarantee for the thermal insulation effect of the thermal insulation pad 30.

[0208] In a specific embodiment, the thickness of the first surface layer 31 can be 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm or 0.1 μm, etc. The specific size of the thickness of the first surface layer 31 is not limited here, and it can be designed according to the requirements.

[0209] In some embodiments, Figure 4 and Figure 7 As shown, the thickness of the second surface layer 32 is 0.01 μm-0.1 μm.

[0210] The thickness of the second surface layer 32 is controlled within the above range so that the second surface layer 32 has a suitable size. Within this size range, the second surface layer 32 can provide good protection for the internal thermal insulation layer 33, the first reflective layer 35 and the second reflective layer 36, so that the thermal insulation pad 30 has good structural strength and structural stability. At the same time, the excessive thickness of the second surface layer 32 will not cause the sizes of the first gap 301 and the second gap 302 to be too small, or the thickness of the thermal insulation layer 33 to be too small, thereby providing a guarantee for the thermal insulation effect of the thermal insulation pad 30.

[0211] In a specific embodiment, the thickness of the second surface layer 32 can be 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm or 0.1 μm, etc. The specific size of the thickness of the second surface layer 32 is not limited here, and it can be designed according to the requirements.

[0212] It can be understood that in a specific embodiment, within the above thickness range, the thickness of the first surface layer 31 may be equal to the thickness of the second surface layer 32 , or the thickness of the first surface layer 31 may be unequal to the thickness of the second surface layer 32 .

[0213] In some embodiments, both the first surface layer 31 and the second surface layer 32 are insulating layers.

[0214] In this way, the first surface layer 31 and the second surface layer 32 are both set as insulating layers, so that the thermal insulation pad 30 can be insulated, so as to reduce the short circuit risk inside the battery device 1 and provide protection for the normal use of the battery device 1.

[0215] In some embodiments, the first surface layer 31 is a polyimide surface layer, a polyethylene terephthalate surface layer, a polypropylene surface layer, a polycarbonate surface layer, a polyvinyl chloride surface layer or a polyurethane surface layer.

[0216] In some embodiments, the second surface layer 32 is a polyimide surface layer, a polyethylene terephthalate surface layer, a polypropylene surface layer, a polycarbonate surface layer, a polyvinyl chloride surface layer, or a polyurethane surface layer.

[0217] It can be understood that in a specific embodiment, the material of the first surface layer 31 can be the same as the material of the second surface layer 32 , or the material of the first surface layer 31 can be different from the material of the second surface layer 32 .

[0218] Another embodiment of the present application further provides an electrical device, including the battery device provided by the above embodiments.

[0219] The electric device of the present application adopts the above-mentioned battery device 1, so it at least includes all the beneficial effects of the above-mentioned battery device 1, which will not be described in detail here.

[0220] Please also read Figures 2 to 7 , two specific battery devices 1 are provided below in combination with specific embodiments:

[0221] Embodiment 1:

[0222] This embodiment provides a battery device 1 , which includes a plurality of battery cells 10 and a thermal insulation pad 30 . The thermal insulation pad 30 is disposed between two adjacent battery cells 10 .

[0223] Among them, the thermal insulation pad 30 includes a first surface layer 31, a second surface layer 32, a thermal insulation layer 33, a first reflecting layer 35, a second reflecting layer 36, a first separator 37, and a second separator 38. The first separator 37 and the second separator 38 are both annular parts. The thermal insulation layer 33 is arranged between the first surface layer 31 and the second surface layer 32. The first reflecting layer 35 covers the surface of the thermal insulation layer 33 facing the first surface layer 31. The second reflecting layer 36 covers the surface of the thermal insulation layer 33 facing the second surface layer 32. The first separator 37 is sandwiched between the first surface layer 31 and the first reflecting layer 35. A first gap 301 is formed between the first surface layer 31, the first separator 37 and the first reflecting layer 35. The second separator 37 is sandwiched between the second surface layer 32 and the second reflecting layer 36. A second gap 302 is formed between the second surface layer 32, the second separator 38 and the second reflecting layer 36.

[0224] The first surface layer 31 and the second surface layer 32 are both polyurethane layers, the thickness of the first surface layer 31 and the second surface layer 32 are both 0.1 μm, the first separator 37 and the second separator 38 are both silicone rubber parts and the thickness is 0.5 μm, and the size of the first gap 301 and the second gap 302 are both 0.5 μm. The first reflective layer 35 and the second reflective layer 36 are both slurry layers composed of titanium dioxide, polyvinylidene fluoride, and N-methylpyrrolidone, wherein the content of titanium dioxide is 95%, and the thickness of the first reflective layer 35 and the second reflective layer 36 are both 0.2 μm. The heat insulation layer 33 is a composite material layer of silica ceramic fiber felt and silica, and the thickness of the heat insulation layer 33 is 2.7 mm, the porosity is 87.4%, and the thermal conductivity coefficient at room temperature is 0.03 W / (m·K). At the same time, three rows of accommodating holes 34 with a hole diameter of 1 mm are evenly spaced in the middle of the thermal insulation layer 33, and the number of accommodating holes 34 in each row is 3, that is, there are 9 accommodating holes 34 evenly spaced in the middle of the thermal insulation layer 33, and each accommodating hole 34 is filled with a heat-absorbing medium, which is a mixed medium of ammonium bicarbonate, polyvinylidene fluoride, and N-methylpyrrolidone, wherein the ammonium bicarbonate content is 95%, and the filling rate of the heat-absorbing medium in the accommodating holes 34 is about 97%.

[0225] Embodiment 2:

[0226] This embodiment provides another battery device 1 , which includes a plurality of battery cells 10 and a thermal insulation pad 30 . The thermal insulation pad 30 is disposed between two adjacent battery cells 10 .

[0227] Different from the above-mentioned embodiment 1, in this embodiment, the heat-absorbing medium filled in each receiving hole 34 is a mixed medium composed of magnesium carbonate, polyvinylidene fluoride, and N-methylpyrrolidone, wherein the magnesium carbonate content is 95%, and the filling rate of the heat-absorbing medium in the receiving hole 34 is about 97%.

[0228] Finally, please combine Figures 8 to 12 This embodiment provides the following thermal insulation effect test experiment, which is used to test the thermal insulation performance of the thermal insulation pad 30 in the battery device 1 provided in the above-mentioned embodiment 1 and embodiment 2, so as to illustrate the thermal insulation effect of the thermal insulation pad 30 inside the corresponding battery device 1.

[0229] In this embodiment, the specific experimental device 40 is roughly as follows Figure 8As shown, the experimental device 40 includes a fixture 41 and a pressure gauge 42 disposed on the fixture 41. The experimental device 40 also includes a heating platform 43, a thermal insulation pad 30, an aluminum block 45 and a cushion 46 clamped in the fixture 41, wherein the pressure gauge 42 is suspended in the upper space of the fixture 41, the heating platform 43, the thermal insulation pad 44 to be tested, the aluminum block 45 and the cushion 46 are stacked in sequence from bottom to top, and the cushion 46 is located directly below the pressure gauge 42. In one test experiment, the thermal insulation pad 44 to be tested corresponds to the thermal insulation pad 30 in the battery device 1 provided in Example 1, and in another test experiment, the thermal insulation pad 44 to be tested corresponds to the thermal insulation pad 30 in the battery device 1 provided in Example 2.

[0230] A temperature sensing line is arranged between the insulation pad 44 to be tested and the heating platform 43 and a first temperature sampling point S1 is set. A temperature sensing line is arranged between the insulation pad 44 to be tested and the aluminum block 45 and a second temperature sampling point S2 is set. Each temperature sampling point is led out of the fixture 41 through a temperature sensing line and connected to a multi-channel temperature meter. The test experiment is carried out according to the following steps;

[0231] 1. Record the thickness of the thermal insulation pad 44 to be tested, clean the surface of the heating platform 43 and the aluminum block 45 to make their surfaces as clean as possible;

[0232] 2. Set the temperature of the heating platform 43 to 600° C. and start heating the heating platform 43 to heat up;

[0233] 3. After the temperature of the heating platform 43 is stabilized at 600°C, start the fixture 41 to drive the thermal insulation pad 44 to be tested to move quickly onto the heating platform 43, start the timing, then move the aluminum block 45 to the upper part of the thermal insulation pad 44 to be tested, and apply a stress of 0.9±0.04MPa to the thermal insulation pad 30, and the pressure is continuously applied for 5min;

[0234] 4. After 5 minutes, the pressure is released to 0.03 MPa, and the thickness of the thermal insulation pad 44 to be tested is detected with a plug gauge, and the thickness retention rate is calculated;

[0235] 5. After keeping warm for 20 minutes, turn off the multi-channel temperature measuring instrument first, then turn off the heating platform 43, and then use a plug gauge to measure the thickness of the insulation pad 44 to be tested and record it, and keep the insulation pad 30 sample;

[0236] 6. Experimental result processing: record the thickness of the thermal insulation pad 44 to be tested and the temperature of the cold surface (the cold surface is the side of the thermal insulation pad 44 to be tested facing the aluminum block 45) of the thermal insulation pad 44 to be tested under 0.9 MPa and after 5 minutes, organize the experimental data, and analyze the endothermic decomposition effect of the thermal insulation pad 44 to be tested.

[0237] Among them, the endothermic decomposition effect of the thermal insulation pad 44 to be tested is mainly analyzed by a thermogravimetric analyzer (TGA) and a differential scanning calorimeter (DSC). Thermogravimetric analysis refers to a thermal analysis technique that measures the relationship between the mass and temperature change of the sample to be tested under program temperature control conditions, which can be used to study the thermal stability and composition of the material. The working principle of the differential scanning calorimeter is to analyze the thermal properties of the sample by measuring the heat difference between the sample and the reference. In the DSC test, the sample and the reference are placed under the same temperature program (such as linear heating, cooling or constant temperature), and the thermal effect information of the sample is obtained by measuring the heat difference between the two. When the sample undergoes an endothermic or exothermic reaction, a temperature difference will be generated between the sample end and the reference end. This temperature difference is converted into an electrical signal and recorded to form a DSC curve.

[0238] The experimental results are as follows Figures 9 to 12 , and as shown in Table 1, it should be noted that in Table 1, the thermal decomposition temperature refers to the temperature when the insulation pad 44 to be tested begins to decompose when heated, the endothermic platform refers to the process in which the insulation pad 44 to be tested continues to absorb heat within a certain temperature range and the heat absorption rate is relatively stable, the endothermic platform time refers to the time that the insulation pad 44 to be tested continues to absorb heat stably within a certain temperature range, and the endothermic platform temperature is the temperature corresponding to the endothermic platform time.

[0239] Table 1

[0240]

[0241] like Fig. 9 , Fig.10 As shown in Table 1, according to the experimental results, when the thermal insulation pad 44 to be tested is the thermal insulation pad 30 of the battery device 1 provided in Example 1, the temperature at which thermal decomposition occurs is 194°C, the endothermic platform time is greater than 20 minutes, and the endothermic platform temperature is 104°C. During the experiment, the thermal insulation pad 44 to be tested begins to endothermically decompose at 194°C, and the cold surface of the thermal insulation pad 44 to be tested has an endothermic platform of more than 20 minutes, and the platform temperature can be maintained at 104°C for a long time, indicating that the thermal insulation pad 30 in the battery device 1 of Example 1 has a good thermal insulation effect, and after the internal absorption medium has completed the endothermic decomposition, the thermal insulation pad 30 still has a good thermal insulation performance.

[0242] like Fig.11 , Fig.12As shown in Table 1, when the thermal insulation pad 44 to be tested is the thermal insulation pad 30 of the battery device 1 provided in Example 2, the temperature at which thermal decomposition occurs is 298°C, the endothermic platform time is greater than 20 minutes, and the endothermic platform temperature is 93°C. During the experiment, the thermal insulation pad 30 to be tested begins to endothermically decompose at 298°C, the cold surface of the thermal insulation pad 30 has an endothermic platform of more than 20 minutes, and the platform temperature can be maintained at 93°C for a long time, indicating that the thermal insulation pad 30 in the battery device 1 of Example 2 also has a good thermal insulation effect, and after the internal absorption medium has completed the endothermic decomposition, the thermal insulation pad 30 still has a good thermal insulation performance.

[0243] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0244] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery device, characterized in that: include: Multiple battery cells; A heat insulation pad is provided between two adjacent battery cells; The thermal insulation pad comprises a first surface layer, a second surface layer, and a thermal insulation layer disposed between the first surface layer and the second surface layer, wherein at least a middle portion of the thermal insulation layer is provided with a plurality of accommodating holes, and the accommodating holes are filled with a heat absorbing medium; The thermal insulation pad further comprises a first reflecting layer and a second reflecting layer, wherein the first reflecting layer covers the surface of the thermal insulation layer facing the first surface layer, and the second reflecting layer covers the surface of the thermal insulation layer facing the second surface layer, the first reflecting layer is spaced apart from the first surface layer and a first gap is formed between the first reflecting layer and the first surface layer, and the second reflecting layer is spaced apart from the second surface layer and a second gap is formed between the second reflecting layer and the second surface layer; The thermal insulation pad further includes a first separator disposed between the first surface layer and the first reflective layer, wherein the first separator is sandwiched between the first surface layer and the first reflective layer at at least two opposite sides of the thermal insulation pad, and the first surface layer, the first separator and the first reflective layer surround and form the first gap; The thermal insulation pad also includes a second separator arranged between the second surface layer and the second reflecting layer. The second separator is clamped between the second surface layer and the second reflecting layer at at least two opposite sides of the thermal insulation pad. The second surface layer, the second separator and the second reflecting layer are arranged to form the second gap.

2. The battery device according to claim 1, characterized in that: An opening is provided on at least one side surface of the thermal insulation layer, and the accommodating hole is communicated with the opening along the thickness direction of the thermal insulation pad.

3. The battery device according to claim 1, characterized in that: There are multiple accommodating holes, and the multiple accommodating holes are evenly distributed in the middle of the thermal insulation layer.

4. The battery device according to claim 1, characterized in that: The heat absorbing medium comprises a solid heat absorbing medium, and the solid heat absorbing medium is at least partially decomposed into gas by heat when the temperature reaches a threshold value.

5. The battery device according to claim 4, characterized in that: The heat absorbing medium includes one or more of carbonate, bicarbonate, phosphate and hydrogen phosphate.

6. The battery device according to claim 5, characterized in that: The heat absorbing medium also includes an adhesive, and the adhesive is mixed with one or more of carbonate, bicarbonate, phosphate, and hydrogen phosphate to make the heat absorbing medium adhere to the containing hole.

7. The battery device according to claim 6, characterized in that: The adhesive includes one or more of water glass, silica sol, ethyl silicate, polyvinylidene fluoride, polyacrylic acid, and polyvinyl pyrrolidone.

8. The battery device according to claim 4, characterized in that: The filling rate of the heat absorbing medium in the containing hole is greater than 95%.

9. The battery device according to claim 1, characterized in that: The aperture of the receiving holes is 0.01 mm to 1 mm, and / or the sum of the cross-sectional areas of the receiving holes is less than or equal to one tenth of the surface area of ​​the thermal insulation layer.

10. The battery device according to any one of claims 1 to 9, characterized in that: The heat insulation layer is a composite material layer of fiber material and porous powder ceramics.

11. The battery device according to claim 10, characterized in that: The fiber material includes one or more of pre-oxidized silk fiber felt, ceramic fiber felt, glass fiber felt, high silica fiber felt, basalt fiber felt, carbon fiber felt, spandex fiber felt, polyethylene terephthalate fiber felt, polyester fiber felt, and nylon fiber felt; And / or, the porous powder ceramic includes one or more of silicon dioxide, zirconium oxide, and aluminum oxide.

12. The battery device according to claim 10, characterized in that: The porosity of the thermal insulation layer is 80% to 99%.

13. The battery device according to any one of claims 1 to 9, characterized in that: The room temperature thermal conductivity of the heat insulation layer is less than 0.23 W / (m·K).

14. The battery device according to any one of claims 1 to 9, characterized in that: The thickness of the thermal insulation layer is 1 mm to 10 mm.

15. The battery device according to any one of claims 1 to 9, characterized in that: The side edge of the first surface layer is sealed to the side edge of the second surface layer to seal the thermal insulation layer.

16. The battery device according to any one of claims 1 to 9, characterized in that: The first reflective layer is a mixed layer of a high temperature resistant resin and a heat reflective material, and / or the second reflective layer is a mixed layer of a high temperature resistant resin and a heat reflective material.

17. The battery device according to claim 16, characterized in that: The high temperature resistant resin includes one or more of polyimide resin, phenolic resin, silicone resin, epoxy resin, polybenzimidazole resin, and polyetheretherketone resin; And / or, the heat reflective material includes one or more of carbon black, SiC powder, titanium dioxide, potassium hexatitanate whisker, zircon, ilmenite powder, and inorganic ceramic fiber.

18. The battery device according to any one of claims 1 to 9, characterized in that: The thickness of the first reflective layer is 0.01 μm to 1.0 μm, and / or the thickness of the second reflective layer is 0.01 μm to 1.0 μm.

19. The battery device according to any one of claims 1 to 9, characterized in that: Along the thickness direction of the thermal insulation pad, the size of the first gap is 0.5 μm to 1.0 μm, and / or the size of the second gap is 0.5 μm to 1.0 μm.

20. The battery device according to any one of claims 1 to 9, characterized in that: The first partition and the second partition are both elastic members.

21. The battery device according to any one of claims 1 to 9, characterized in that: The thickness of the first surface layer is 0.01 μm to 0.1 μm, and / or the thickness of the second surface layer is 0.01 μm to 0.1 μm.

22. The battery device according to any one of claims 1 to 9, characterized in that: The first surface layer and the second surface layer are both insulating layers.

23. An electrical device, characterized in that: A battery device comprising a plurality of battery devices according to any one of claims 1 to 22.

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