Composite Material and Battery Device Containing the Same

Abstract

The present invention discloses a composite material for manufacturing a housing of a battery device, including a base material layer (10) and a first fireproof coating (20) coated on at least a part of the surface of the base material layer (10), wherein the first fireproof coating (20) has a thickness of 0.3 mm to 1.5 mm. The composite material has both the advantages of fireproof and lightweight. Furthermore, the composite material further has the advantage of heat insulation.

Description

Technical Field

[0001] The present invention relates to the field of batteries. More specifically, the present invention relates to a composite material for manufacturing a housing of a battery device, and a battery device including the housing.

Background Art

[0002] In recent years, thermal runaway accidents of battery devices have occurred occasionally in new energy vehicles. Therefore, in the automotive industry, the requirements for fire prevention of battery devices are becoming increasingly high. Furthermore, in order to improve the driving range, the requirements for lightweight battery devices in the automotive industry are also increasing.

[0003] Therefore, in order to better meet the requirements of the performance of modern new energy vehicles, it is necessary to continuously develop a new composite material with lightweight and excellent fire prevention performance for manufacturing the housing of the battery device.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of the above problems, an object of the present invention is to provide a composite material having lightweight and excellent fire prevention performance.

Means for Solving the Problems

[0005] In a first aspect of the present invention, there is provided a composite material for manufacturing a housing of a battery device, a base material layer (10), and a first fireproof coating (20) coated on at least a part of the surface of the base material layer (10) The composite material is characterized in that the first fireproof coating (20) has a thickness of 0.3 mm to 1.5 mm.

[0006] In some embodiments, the composite material further includes a fiber-reinforced resin layer (30), the fiber-reinforced resin layer (30) is located between the base material layer (10) and the first fireproof coating (20), and the fiber-reinforced resin layer (30) includes reinforcing fibers and a resin surrounding the reinforcing fibers.

[0007] In a further embodiment, the composite material further includes a dielectric layer (40), and the dielectric layer (40) is located between the base material layer (10) and the first fireproof coating (20) or between the base material layer (10) and the fiber-reinforced resin layer (30).

[0008] In still a further embodiment, the composite material further includes a panel layer (50), the panel layer (50) is located on the surface of the first fireproof coating (20) away from the base material layer (10), and the panel layer (50) is made of a resin material.

[0009] In still a further embodiment, the composite material further includes a second fireproof coating (20'), the second fireproof coating (20') is coated on at least a part of the surface of the base material layer (10) on the side opposite to the first fireproof coating (20), and the second fireproof coating (20') has a thickness of 0.3 mm to 1.5 mm.

[0010] In still a further embodiment, the composite material further includes a heat insulation layer (60), the heat insulation layer (60) is disposed on the surface of the base material layer (10) on the side opposite to the first fireproof coating (20) or on the surface of the second fireproof coating (20'), and the heat insulation layer (60) is made of a porous material.

[0011] Furthermore, the present invention provides a housing for a battery device, wherein the material of the housing is the above-described composite material, and the housing is an upper cover, a bottom plate and / or a side plate of the battery device.

[0012] Furthermore, the present invention further provides a battery device including the housing, such as a battery cell, a battery module, and a battery pack.

[0013] Beneficial effects The composite material of the present invention is not only lightweight but also excellent in fireproof performance, which can not only significantly reduce the total weight of the battery device but also improve the safety factor of the battery device.

[0014] To more clearly explain the embodiments of the present invention, the drawings required in connection with the description of the embodiments are briefly introduced below. Obviously, the drawings in the following description show only some embodiments of the present invention. Those skilled in the art can also obtain other embodiments by making simple replacements / modifications based on those drawings.

Brief description of the drawings

[0015]

Figure 1

Figure 2

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Figure 8

[0016] In the drawings, 10: Substrate layer 20: First fireproof coating 20’: Second fireproof coating 30: Fiber-reinforced resin layer 40: Dielectric layer 50: Panel layer 60: Heat insulation layer 70: Waterproof layer.

Embodiments for Carrying out the Invention

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the protection scope of the present invention.

[0018] As described above, the current housing material of the battery device has problems such as heavy weight and insufficient fireproof performance.

[0019] To address such problems, referring to FIG. 1, the present invention provides a composite material 100 for manufacturing the housing of a battery device, including a base material layer 10 and a first fireproof coating 20, where the first fireproof coating 20 is coated on at least a part of the surface of the base material layer and has a thickness of 0.3 mm to 1.5 mm.

[0020] The first fireproof coating has strong fireproof properties and can prevent combustion for a specific period of time by delaying the transmission of high temperature to the surrounding environment. The housing manufactured by coating the fireproof coating on the base material layer can act as a protection barrier, so as to timely block the spread of the high temperature generated by the local thermal runaway of the battery device to the surrounding area, thereby suppressing or delaying the ignition and explosion of the battery device.

[0021] Furthermore, in the present invention, the first fireproof coating is ultra-thin, that is, its thickness is 0.3 mm to 1.5 mm, for example, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm or 1.5 mm. If the thickness of the first fireproof coating is too thin, it will affect the heat insulation performance and fireproof performance of the composite material, and if the thickness of the first fireproof coating is too thick, it will affect the weight of the composite material. On the other hand, when the first fireproof coating is a (micro) intumescent fireproof coating, an excessive coating thickness causes excessive expansion of the fireproof coating, occupying limited space. The inventor of the present invention has found that by setting the thickness of the first fireproof coating to be 0.3 mm to 1.5 mm, the composite material according to the present invention has both the advantages of fireproof and lightweight.

[0022] In some embodiments, the first fireproof coating covers at least a part of the surface of the base material layer, for example, 30% to 100% of the surface of the base material layer. When the composite material 100 is used to manufacture the housing of the battery pack, it is preferable to provide the first fireproof coating only at the position of the housing corresponding to the pressure relief valve (also referred to as the exhaust valve) on the battery module inside the battery pack. This is because when thermal runaway of the battery module occurs, the position of the housing corresponding to the pressure relief valve is the position that receives the thermal shock of the high-temperature gas, and providing the first fireproof coating only at the position of the housing corresponding to the pressure relief valve can reduce the amount of fireproof paint used on the housing surface.

[0023] In some embodiments, the base material layer may be a metal material or a resin material, that is, the base material layer may be made of a metal material or a resin material. The base material layer, as a structural member of the battery device, must have a specific mechanical strength to protect the internal battery elements from damage when they are subjected to external impact or compression and / or support the weight of the internal battery elements. Furthermore, the base material layer also has a waterproof effect. Exemplary metal materials include aluminum alloy, iron, steel, aluminum, etc. Exemplary resin materials include polyurethane, polyurea, epoxy resin, unsaturated resin, etc.

[0024] In some embodiments, the thickness of the base material layer is 0.3 mm to 3.5 mm. In particular, when the base material layer is made of a metal material, its thickness is preferably 0.5 mm to 2 mm, such as 0.5 mm, 1 mm, 1.5 mm or 2 mm. When the base material layer is made of a resin material, its thickness is preferably 1 mm to 3.5 mm, such as 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm or 3.5 mm. As described above, since the first fireproof coating has excellent heat insulation performance and fireproof performance, it is possible to set the thickness of the base material layer of the present invention relatively low to meet the expectation of a lightweight battery device.

[0025] In some embodiments, the first fireproof coating is a fine expansion type fireproof coating. The fine expansion type fireproof coating has an expansion coefficient of 2 to 20 times, preferably 3 to 15 times. The expansion coefficient relates to the ratio of the thickness of the fireproof coating after thermal expansion to the thickness before expansion. When high temperature is generated due to local thermal runaway of the battery device, the first fireproof coating expands slightly after heating and can release incombustible gas to reduce the oxygen density inside the battery device. Furthermore, the first fireproof coating can also form an expanded heat insulation layer that is several times to dozens of times thicker than the original coating, such as 2 to 20 times, preferably 3 to 15 times. On the one hand, the formed expanded heat insulation layer isolates the contained battery elements from the surrounding environment and blocks oxygen. On the other hand, due to the fact that the material itself has good heat insulation performance due to its loose nature, it forms a heat insulation barrier to block the diffusion of high temperature to the surrounding area, and thus can protect the underlying base material layer from damage.

[0026] The above-mentioned fine expansion type fireproof coating is made of a fine expansion type fireproof paint. By using the fine expansion type fireproof paint, the formed expanded heat insulation layer is not too thick, thereby avoiding damage to the battery elements contained inside or adjacent to the housing, such as battery modules, battery cells or bare cells, due to excessive expansion of the first fireproof coating, and meeting the requirements of the limited internal space in the battery device.

[0027] Specifically, the fine expansion type fireproof paint mainly contains resin, acid source and blowing agent. Suitable resins include polyurethane, polyurea, epoxy resin, etc., and polyurethane is preferred. The fireproof paint based on resin has characteristics such as excellent adhesion strength, good weather resistance, good water resistance, good leveling properties, etc. Furthermore, due to the absence of substances with a high carbon content, such as expanded graphite, the fine expansion type fireproof coating will not expand excessively after heating.

[0028] When the fireproof coating is exposed to high temperature, the acid source can release incombustible gases, such as sulfur dioxide and ammonia, to dilute the density of the surrounding oxygen and promote the formation of the expansion heat insulation layer. Suitable acid sources include, without limitation, phosphorus-containing compounds and sulfur-containing compounds. Phosphorus-containing compounds include phosphates and phosphate esters, such as sodium phosphate, potassium phosphate or ammonium phosphate, ammonium polyphosphate (APP), monoammonium phosphate, diammonium hydrogen phosphate, tris(2-chloroethyl) phosphate (TCEP), tris(2-chloropropyl) phosphate (TCPP), ammonium pyrophosphate, triphenyl phosphate, etc. Sulfur-containing compounds include sulfonates, such as sodium sulfonate, potassium sulfonate or sulfonic acid, p-toluenesulfonic acid, and sulfates, such as sodium sulfate, potassium sulfate or ammonium sulfate.

[0029] When the fireproof coating is exposed to high temperatures, the blowing agent can generate incombustible gases such as nitrogen and ammonia, further diluting the density of the surrounding oxygen and facilitating the expansion of the fireproof coating. Suitable blowing agents include, without limitation, melamine compounds and boron-containing compounds. Melamine compounds include melamine salts such as melamine cyanurate, melamine formaldehyde, hydroxymethylated melamine, hexamethoxymethyl melamine, melamine monophosphate, di(melamine phosphate), melamine dihydrogen phosphate, etc., and boron-containing compounds include boric acid, borates and borate esters such as ammonium pentaborate, zinc borate, sodium borate, lithium borate, aluminum borate, magnesium borate and borosilicate.

[0030] It should be understood that the above-mentioned fine-expansion type fireproof coating may also include inorganic fillers, other flame retardants, etc. Suitable inorganic fillers include, without limitation, metal oxides, hydroxides and (mineral) salts.

[0031] The base material layer can be preformed into a desired shape by appropriate processing such as cutting and hot pressing. The first fireproof coating is coated on the surface of the base material layer by methods such as roller coating, dip coating, brush coating or spraying to obtain the composite material 100. It should be understood that those skilled in the art can select an appropriate processing method according to the scenario of the specific application. The manufacturing method of the composite material according to the present invention is simple and suitable for the factory assembly line process.

[0032] The composite material of the present invention will be further introduced below with reference to FIGS. 2-5.

[0033] As shown in FIG. 2, in some embodiments, the composite material 200 according to the present invention further includes a fiber-reinforced resin layer 30, and the fiber-reinforced resin layer 30 is located between the base material layer 10 and the first fireproof coating 20, and the fiber-reinforced resin layer 30 includes reinforcing fibers and a resin surrounding the reinforcing fibers.

[0034] Both the above-mentioned reinforcing fibers and resins can be selected from materials known in the art. For example, suitable resin materials include polyurethane, polyurea, epoxy resin, unsaturated resin, etc., and polyurethane resin is preferred. Suitable reinforcing fiber materials include glass fiber, carbon fiber, natural fiber, non-woven fabric, etc., and glass fiber is preferred. By providing the fiber-reinforced resin layer 30 between the base material layer 10 and the first fireproof coating 20, not only can the mechanical strength of the composite material be significantly improved, but also the fiber-reinforced resin layer can, due to its excellent fireproof property, ensure that the composite material retains the integrity of its structure after a fire.

[0035] The thickness of the fiber-reinforced resin layer can be 0.3 mm to 1 mm, for example, 0.3 mm, 0.5 mm, 0.8 mm or 1 mm. Those skilled in the art can select an appropriate thickness according to the specific configuration of the composite material.

[0036] The fiber-reinforced resin layer can be integrally formed by adding reinforcing fibers to the resin and then curing it by hot pressing, or by spraying the resin material onto a reinforcing fiber product (such as a fiber felt) and then curing it by hot pressing. In the manufactured fiber-reinforced resin layer, the resin material is filled in the pores of the reinforcing fibers and surrounds the reinforcing fibers.

[0037] Therefore, the composite material 200 can be manufactured by first laminating the fiber-reinforced resin layer 30 onto the base material layer 10 and hot pressing to join them, and then coating the surface of the fiber-reinforced resin layer with a fireproof paint. It should be understood that those skilled in the art can appropriately adjust the manufacturing process and the order of steps as appropriate.

[0038] As shown in FIG. 3, in some embodiments, when the base material layer 10 is a metal material, the composite material 300 according to the present invention further includes a dielectric layer 40, and the dielectric layer 40 is located between the base material layer 10 and the first fireproof coating 20. As shown in FIG. 4, in some alternative embodiments, the composite material 400 according to the present invention includes both a fiber-reinforced resin layer 30 and a dielectric layer 40, and the dielectric layer 40 is located between the base material layer 10 and the fiber-reinforced resin layer 30.

[0039] The dielectric layer can protect the metal material in the base material layer and has anti-corrosion / waterproof and insulation effects. Suitable materials for the dielectric layer can be epoxy resin, acrylic resin, and other suitable organic coatings.

[0040] The thickness of the dielectric layer is not particularly limited in the present invention and can be adjusted by those skilled in the art according to actual needs. In some embodiments, the thickness of the dielectric layer can be 10 μm to 50 μm, for example, 10 μm, 20 μm, 25 μm, 30 μm, 40 μm or 50 μm.

[0041] The dielectric layer can be formed on the surface of the base material layer by electrophoresis, brush coating, roller coating, spraying, etc. Subsequently, the above-mentioned first fireproof coating is coated on the surface of the dielectric layer to obtain the composite material 300, or the fiber-reinforced resin layer is first laminated on the surface of the dielectric layer and hot-pressed, and then coated with the first fireproof coating to obtain the composite material 400.

[0042] Furthermore, as shown in FIG. 5, in some embodiments, the composite material 500 according to the present invention further includes a panel layer 50, and the panel layer 50 is located on the surface of the first fireproof coating 20 away from the base material layer 10, and the panel layer is a resin material. Suitable resin materials include polyurethane, polyurea, epoxy resin, unsaturated resin, etc.

[0043] By providing a panel layer on the surface of the first fireproof coating, the first fireproof coating can be protected from damage during transportation and use. The panel layer can be joined to the first fireproof coating by hot pressing or the like after being laminated on the surface of the first fireproof coating.

[0044] It can be understood that the panel layer 50 is also arranged on the surface of the first fireproof coating of the composite material as shown in FIGS. 1 to 4, and can protect the first fireproof coating.

[0045] It should also be understood that the above-described embodiments and drawings are merely illustrative, and those skilled in the art can appropriately adjust the combination order and / or amount of materials without departing from the gist of the present invention. For example, in the embodiments described by the above paragraphs and / or shown in FIGS. 1 to 5, the fireproof coating, the fiber-reinforced resin layer, the dielectric layer and / or the panel layer may also be provided on the other side of the base material layer 10. As shown in FIG. 6, the composite material 600 further includes a second fireproof coating 20', and the second fireproof coating 20' is coated on at least a part of the surface of the base material layer 10 on the side opposite to the first fireproof coating 20, and has a thickness of 0.3 mm to 1.5 mm. Optionally, the dielectric layer and / or the fiber-reinforced resin layer may be respectively provided between the base material layer and the second fireproof coating, and the panel layer is provided on the outer surface of the second fireproof coating. The second fireproof coating 20' has the same material, properties, manufacturing process, performance, etc. as the above-described first fireproof coating 20, and thus will not be repeatedly described here.

[0046] Furthermore, as shown in FIG. 7A, the composite material 700 can further include a heat insulation layer 60, the heat insulation layer 60 is disposed on the surface of the base material layer 10 on the side opposite to the first fireproof coating 20, and is made of a porous material. The porous material includes, for example, porous ceramics, glass fiber felt, aerogel, expanded materials (such as expanded graphite), and the like. Optionally, as shown in FIG. 7B, in the composite material 700', the heat insulation layer 60 can also be disposed on the surface of the second fireproof coating 20'. In other specific embodiments, as shown in FIG. 7C, the composite material 700'' includes a first fireproof coating 20, a fiber reinforced resin layer 30, a base material layer 10, a second fireproof coating 20', and a heat insulation layer 60, and they are laminated in sequence.

[0047] It should be understood that although the composite materials shown in FIGS. 7A to 7C only include the base material layer 10, the first fireproof coating 20, the second fireproof coating 20', the fiber reinforced resin layer 30, and the heat insulation layer 60, the composite materials can further include the dielectric layer and / or the panel layer described above.

[0048] The porous material has good heat insulation performance because the pores of the porous material are filled with air or other low thermal conductivity media, which reduces the thermal conductivity of the material to a very low level. By providing a heat insulation layer on the surface of the base material layer 10 on the side opposite to the first fireproof coating 20 or on the surface of the second fireproof coating 20', the composite material has the advantage of heat insulation in addition to the above-mentioned fireproof and lightweight effects, thereby further reducing the impact of the high temperature generated by thermal runaway inside the battery device on the components around the battery device.

[0049] In other embodiments, the composite material further includes a waterproof layer 70, and the waterproof layer is disposed on one or both sides of the fiber reinforced resin layer 30. In the present invention, the thickness of the waterproof layer is 0.01 to 1 mm, preferably 0.02 to 0.3 mm.

[0050] The waterproof layer includes a metal sheet or a plastic sheet known in the art. Preferably, the metal sheet is selected from the group consisting of aluminum alloy, iron, steel, and aluminum. Preferably, the plastic sheet is at least one material selected from the group consisting of polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene (PP), thermoplastic polyurethane (TPU), polyurethane (PU), polyamide (PA), polyvinyl butyral (PVB), and ethylene vinyl acetate copolymer (EVA). In a preferred embodiment, the plastic sheet is selected from polyurethane (PU), more preferably thermoplastic polyurethane (TPU).

[0051] As shown in FIG. 8, the composite material 800 further includes a waterproof layer 70, and the waterproof layer 70 can be disposed between the fiber-reinforced resin layer 30 and the first fireproof coating 20. The composite material 800 can be integrally formed by first laminating a waterproof layer on a reinforced fiber product (such as a fiber felt), spraying a resin material, then curing it by hot pressing, then installing the obtained fiber-reinforced resin layer and the waterproof layer together on a base material layer and hot pressing and joining them, and finally coating the surface of the waterproof layer with a waterproof paint. It should be understood that those skilled in the art can appropriately adjust the manufacturing process and the order of steps as appropriate.

[0052] It should be understood that the composite material can also include one or more waterproof layers and fiber-reinforced resin layers, and the waterproof layer and the fiber-reinforced resin layer can also be located on the other side of the base material layer. Those skilled in the art can appropriately adjust the number and position of the waterproof layer and the fiber-reinforced resin layer according to specific needs. Therefore, the manufacturing method of the composite material is also adjusted accordingly.

[0053] By further providing a waterproof layer in the composite material, the waterproof performance of the composite material can be further improved. In particular, when the composite material is used to manufacture the housing of a battery device, the battery device can still have a good waterproof effect when immersed in water.

[0054] In a second aspect of the present invention, there is provided a housing for a battery device, wherein the material of the housing is the composite material described in the above-described first aspect, and the housing is an upper cover, a bottom plate, and / or a side plate of the battery device. For example, in some embodiments, the composite material is used only to manufacture the upper cover of the battery device, while in other embodiments, the composite material can be used to simultaneously manufacture the upper cover, the bottom plate, and the side plates of the battery device. Further, the battery device includes, for example, battery cells, battery modules, and battery packs.

[0055] In a third embodiment of the present invention, there is further provided a battery cell including a housing and a bare cell located inside the housing, wherein the material of the housing of the battery cell is the composite material described in the above-described first aspect, and a first fireproof coating 20 is located on the side of the housing away from the bare cell.

[0056] In a fourth embodiment of the present invention, there is provided a battery module including a housing and a plurality of battery cells located inside the housing, wherein the housing includes an upper cover, a bottom plate, and side plates, and at least one of the materials of the upper cover, the bottom plate, and the side plates is the composite material described in the above-described first aspect, and a first fireproof coating 20 is located on the side of the housing close to the battery cells. In some embodiments, the battery cells are the battery cells described in the above-described third aspect.

[0057] In a fifth embodiment of the present invention, there is provided a battery pack including a housing and a plurality of battery modules located inside the housing, wherein the housing includes an upper cover, a bottom plate, and side plates, at least one of the materials of the upper cover, the bottom plate, and the side plates is the composite material described in the above-described first embodiment, and a first fireproof coating 20 is located on the side of the housing close to the battery modules. In some embodiments, the battery module is the battery module described in the above-described fourth embodiment.

[0058] In some specific embodiments, the composite material for manufacturing the housing of the battery pack further includes a second fireproof coating 20', the second fireproof coating 20' is coated on at least a part of the surface of the base material layer 10 on the side opposite to the first fireproof coating 20, and the second fireproof coating 20' has a thickness of 0.3 mm to 1.5 mm. That is, the second fireproof coating 20' is located on the side of the housing away from the battery module. In other embodiments, the composite material for manufacturing the housing of the battery pack further includes a heat insulation layer 60, and the heat insulation layer 60 is disposed on the surface of the base material layer (10) on the side opposite to the first fireproof coating 20 or on the surface of the second fireproof coating 20'. The heat insulation layer 60 is made of a porous material. The porous material includes, for example, porous ceramics, glass fiber felt, aerogel, expanded materials (such as expanded graphite), and the like.

[0059] As described above, by providing a heat insulation layer on the surface of the base material layer 10 on the side opposite to the first fireproof coating 20 or on the surface of the second fireproof coating 20', the composite material has the advantage of heat insulation in addition to the above-described fireproof and lightweight effects, thereby further reducing the impact of the high temperature generated by thermal runaway inside the battery pack on the components around the battery pack.

[0060] In some embodiments, the battery module inside the above-described battery pack further includes a pressure relief valve, and the first fireproof coating 20 is disposed only at the position of the housing corresponding to the pressure relief valve. This is because when thermal runaway of the battery module occurs, the housing corresponding to the pressure relief valve first receives the thermal shock of the high-temperature gas, and installing the first fireproof coating only at the position of the housing corresponding to the pressure relief valve can reduce the amount of fireproof paint used on the housing surface.

[0061] As described above, the composite material described by the first aspect of the present invention has both the advantages of fireproof and lightweight. Therefore, when the bare cell, battery cell, and battery module included in the housing undergo thermal runaway, the housing can prevent the high temperature from spreading outward to adjacent battery cells or battery modules. In particular, the housing can also protect the bare cell, battery cell, and battery module included therein from external mechanical shocks and the influence of high temperatures, ensuring the safe use of the battery device.

[0062] The above describes the basic principles and exemplary embodiments of the present invention. Those skilled in the art will understand that the above description is only for the purpose of explaining the present invention, and the present invention is not limited to the above-described embodiments. Without departing from the gist and scope of the present invention, the present invention can also have various variations and improvements, all of which are within the scope of protection claimed by the present invention.

Claims

1. A composite material for manufacturing a battery device housing, Substrate layer (10), and A first fire-resistant coating (20) is applied to at least a portion of the surface of the base material layer (10). The composite material comprising the first fire-resistant coating having a thickness of 0.3 mm to 1.5 mm.

2. The composite material according to claim 1, wherein the composite material further comprises a fiber-reinforced resin layer (30), the fiber-reinforced resin layer (30) is located between the base material layer (10) and the first fire-resistant coating (20), and the fiber-reinforced resin layer (30) comprises reinforcing fibers and a resin surrounding the reinforcing fibers.

3. The composite material according to claim 2, characterized in that the thickness of the fiber-reinforced resin layer (30) is 0.3 mm to 1 mm.

4. The composite material according to claim 1 or 2, characterized in that the base material layer (10) is made of a resin material or a metal material.

5. The composite material according to claim 1 or 2, characterized in that the thickness of the base material layer (10) is 0.3 mm to 3.5 mm.

6. The composite material according to claim 1 or 2, characterized in that the first fire-resistant coating (20) is a micro-expansion type fire-resistant coating having an expansion coefficient of 2 to 20 times.

7. The composite material according to claim 6, characterized in that the micro-expansion type fire-resistant coating is made of a micro-expansion type fire-resistant paint, the micro-expansion type fire-resistant paint comprises a resin, an acid source and an expander, the acid source comprises a phosphorus-containing compound and a sulfur-containing compound, and the expander comprises a melamine compound and a boron-containing compound.

8. The composite material according to claim 7, characterized in that the micro-expansion type fire-resistant coating further comprises an inorganic filler.

9. The composite material according to claim 1 or 2, characterized in that the base material layer (10) is made of a metal material, and the composite material further includes a dielectric layer (40), wherein the dielectric layer (40) is located between the base material layer (10) and the first fire-resistant coating (20), or between the base material layer (10) and the fiber-reinforced resin layer (30).

10. The composite material according to claim 1 or 2, wherein the composite material further comprises a panel layer (50), the panel layer (50) located on the surface of the first fire-resistant coating (20) separate from the base material layer (10), and the panel layer (50) is made of a resin material.

11. The composite material according to claim 1 or 2, wherein the composite material further comprises a second fire-resistant coating (20'), the second fire-resistant coating (20') covering at least a portion of the surface of the substrate layer (10) opposite to the first fire-resistant coating (20), and the second fire-resistant coating (20') having a thickness of 0.3 mm to 1.5 mm.

12. The composite material according to claim 1 or 2, wherein the composite material further comprises a waterproof layer (70), the waterproof layer (70) is disposed on one or both sides of the fiber-reinforced resin layer (30), and the waterproof layer has a thickness of 0.01 to 1 mm.

13. The composite material according to claim 11, further comprising a thermal insulation layer (60), wherein the thermal insulation layer (60) is disposed on the surface of the base material layer (10) opposite to the first fire-resistant coating (20), or on the surface of the second fire-resistant coating (20'), and the thermal insulation layer (60) is made of a porous material.

14. A housing for a battery device, wherein the material of the housing is a composite material according to any one of claims 1 to 3, and the housing is an upper cover, bottom plate and / or side plate of the battery device.

15. The housing according to claim 14, characterized in that the battery device includes a battery cell, a battery module, and a battery pack.

16. A battery cell comprising a housing and bare cells located inside the housing, wherein the material of the housing of the battery cell is a composite material according to any one of claims 1 to 3, and the first fire-resistant coating (20) is located on the side of the housing away from the bare cells.

17. A battery module comprising a housing and a plurality of battery cells located inside the housing, wherein the housing comprises an upper cover, a bottom plate and a side plate, at least one material of the upper cover, the bottom plate and the side plate is a composite material according to any one of claims 1 to 3, and the first fire-resistant coating (20) is located on the side of the housing that is close to the battery cells.

18. A battery pack comprising a housing and a plurality of battery modules located inside the housing, wherein the housing comprises an upper cover, a bottom plate and a side plate, at least one of the materials of the upper cover, the bottom plate and the side plate is a composite material according to any one of claims 1 to 3, and the first fire-resistant coating (20) is located on the side of the housing that is close to the battery modules.

19. The battery pack according to claim 18, characterized in that the battery module includes a pressure relief valve, and the first fireproof coating (20) in the composite material is positioned only at the housing location corresponding to the pressure relief valve.

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