Heat-resistant protective material and battery

Abstract

This application discloses a heat-resistant protective material and a battery. The heat-resistant protective material includes a functional layer, and the functional layer includes a first resin and a filler dispersed in the first resin. By the above means, it can withstand the thermal shock when the battery cell burns and explodes, and can maintain the structural integrity without being destroyed even when receiving the thermal shock, thereby providing effective heat insulation and protection for the battery pack.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and specifically to a heat-resistant protective material and a battery.

Background Art

[0002] As battery technology is increasingly widely applied in daily life, the safety performance of batteries has also been attracting more and more attention. The safety problem of batteries is substantially closely related to thermal runaway. When thermal runaway occurs in a battery, it may pose a danger to the safety of the entire vehicle and the safety of the passengers' bodies.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of this application is to provide a heat-resistant protective material and a battery that can protect the battery housing from airflow impact and high-temperature melting during thermal runaway of the battery and enhance the safety performance of the battery.

Means for Solving the Problems

[0004] To solve the above technical problems, the technical solution adopted in this application is to provide a heat-resistant protective material including a functional layer, and the functional layer includes a first resin and a filler dispersed in the first resin.

[0005] In one embodiment of this application, the mass content of carbon element in the first resin is greater than 40%. The filler is chopped fiber, and the volume ratio of the chopped fiber in the functional layer is 50 - 80%. The chopped fiber includes one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, boron carbon fiber, and carbon nanotube. Alternatively, the filler is a first heat-reflective filler, and the volume ratio of the first heat-reflective filler in the functional layer is 45 - 75%. The first heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium.

[0006] In one embodiment of the present application, the mass content of carbon element in the first resin is greater than 40%, the filler includes a first silicon-containing filler, and the weight ratio of the first resin to the first silicon-containing filler is 1:3 to 1:1.

[0007] In one embodiment of the present application, the first silicon-containing filler includes one or a combination of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, talc.

[0008] In one embodiment of the present application, the first silicon-containing filler includes silica aerogel powder and mica powder, and the mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:1.

[0009] In one embodiment of the present application, the first silicon-containing filler includes silica and aluminum oxide. The usage amount of the silica is 50 to 80 wt% of the first silicon-containing filler, and the usage amount of the aluminum oxide is 10 to 30 wt% of the first silicon-containing filler.

[0010] In one embodiment of the present application, the filler further includes a first high-temperature fusing agent, and the usage amount of the first high-temperature fusing agent is 10 wt% to 40 wt% of the first silicon-containing filler.

[0011] In one embodiment of the present application, the first high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, aluminum silicon powder, and the material of the first high-temperature fusing agent is different from the material of the first silicon-containing filler.

[0012] In one embodiment of the present application, the filler further includes a first lubricant, and the usage amount of the first lubricant is 10 to 40 wt% of the first silicon-containing filler.

[0013] In one embodiment of the present application, the functional layer further includes a first ceramic precursor, and the ratio of the volume of the first ceramic precursor to the sum of the volumes of the first ceramic precursor and the first resin is less than 50%, or the ratio of the mass of the first ceramic precursor to the sum of the masses of the first ceramic precursor and the first resin is less than 50%.

[0014] In one embodiment of the present application, the first ceramic precursor includes one or more of polysilazane resin, polyborosilazane resin, and polycarbosilane resin.

[0015] In one embodiment of the present application, the filler further includes chopped fibers, and the usage amount of the chopped fibers is 0 to 15 wt% of the first silicon-containing filler.

[0016] In one embodiment of the present application, the chopped fibers include one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, boron carbon fiber, and carbon nanotube. The chopped fibers have a length of 0.05 to 30 mm and a diameter of 1 to 15 μm.

[0017] In one embodiment of the present application, the filler further includes a first heat-reflective filler, and the usage amount of the first heat-reflective filler is 0 to 5 wt% of the first silicon-containing filler.

[0018] In one embodiment of the present application, the first heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium.

[0019] In one embodiment of the present application, the heat-resistant protective material further includes a reinforcing layer laminated with the functional layer, and the thickness ratio of the functional layer to the reinforcing layer is (8 to 10):(1 to 4).

[0020] In one embodiment of the present application, the reinforcing layer is a fiber matrix, or the reinforcing layer includes a fiber matrix and a second resin, and the second resin is dispersed in the voids of the fiber matrix and / or on the surface of the fiber matrix to form a composite layer.

[0021] In one embodiment of the present application, when the reinforcing layer includes a fiber matrix and a second resin, the mass content of carbon element in the second resin is greater than 40%, the fiber matrix includes a fiber cloth and / or a fiber felt, and the fibers of the fiber matrix include one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, boron carbon fiber, and carbon nanotube.

[0022] In one embodiment of the present application, the first resin includes one or more combinations of phenol resin, furfural acetone resin, benzoxazine resin, furan resin, polyurea, and phenol-modified epoxy resin, and / or the second resin includes one or more combinations of phenol resin, furfural acetone resin, benzoxazine resin, furan resin, polyurea, and phenol-modified epoxy resin.

[0023] In one embodiment of the present application, a first viscosity modifier is dispersed in the first resin, and the usage amount of the first viscosity modifier is 1 to 10% of the volume of the first resin, and / or a first curing agent is dispersed in the first resin, and / or a first flame retardant is dispersed in the first resin, and the usage amount of the first flame retardant is 5 to 40% of the mass of the first resin, and / or a second viscosity modifier is dispersed in the second resin, and the usage amount of the second viscosity modifier is 1 to 10% of the volume of the second resin, and / or a second curing agent is dispersed in the second resin, and / or a second flame retardant is dispersed in the second resin, and the usage amount of the second flame retardant is 5 to 40% of the mass of the second resin.

[0024] In one embodiment of the present application, the reinforcing layer includes a fiber matrix and a second resin, a phase change material is further dispersed in the second resin, and the usage amount of the phase change material is 5% to 20% of the volume of the fiber matrix.

[0025] In one embodiment of the present application, the fiber matrix includes a fiber cloth, and the fiber cloth is one or more of a fiber twill fabric, a fiber satin fabric, a fiber uniaxial fabric, and a fiber multi-axial fabric.

[0026] In one embodiment of the present application, the reinforcing layer includes a fiber matrix and a second resin, the reinforcing layer further includes a second ceramic precursor, and the ratio of the volume of the second ceramic precursor to the sum of the volumes of the second ceramic precursor and the second resin is less than 50%, or the ratio of the mass of the second ceramic precursor to the sum of the masses of the second ceramic precursor and the second resin is less than 50%.

[0027] In one embodiment of the present application, the second ceramic precursor includes one or more of a polysilazane resin and a polyborosilazane resin.

[0028] In one embodiment of the present application, the fiber matrix includes a first fiber matrix and a second fiber matrix, the second resin is dispersed in the voids of the first fiber matrix and / or covers two opposite surfaces of the first fiber matrix to form a first composite layer, the second ceramic precursor is dispersed in the voids of the second fiber matrix and / or covers two opposite surfaces of the second fiber matrix to form a second composite layer, the first composite layer and the second composite layer are provided in a stacked manner to form a stacked structure, or two of the first composite layers sandwich at least one of the second composite layers to form a stacked structure, or two of the second composite layers sandwich at least one of the first composite layers to form a stacked structure.

[0029] In one embodiment of the present application, the mixture of the second resin and the second ceramic precursor is dispersed within the voids of the fiber matrix and / or covers two opposing surfaces of the fiber matrix.

[0030] In one embodiment of the present application, the second ceramic precursor is applied to one surface of the composite layer or to two opposing surfaces of the composite layer.

[0031] In one embodiment of the present application, the reinforcing layer includes a fiber matrix and a second resin, the reinforcing layer further includes a second silicon-containing filler, and the second silicon-containing filler occupies 40% to 70% of the volume of the fiber matrix.

[0032] In one embodiment of the present application, the second silicon-containing filler includes one or a combination of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, and talc.

[0033] In one embodiment of the present application, the second silicon-containing filler includes silica aerogel powder and mica powder, and the mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:1.

[0034] In one embodiment of the present application, the second silicon-containing filler includes silica and aluminum oxide, the usage amount of the silica is 50% to 80 wt% of the second silicon-containing filler, and the usage amount of the aluminum oxide is 10% to 30 wt% of the second silicon-containing filler.

[0035] In one embodiment of the present application, the second silicon-containing filler is applied to the surface of the composite layer or embedded in the second resin.

[0036] In one embodiment of the present application, the reinforcing layer further includes a second high-temperature fusing agent, and the usage amount of the second high-temperature fusing agent is 10 wt% to 40 wt% of the second silicon-containing filler.

[0037] In one embodiment of the present application, the second high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, and aluminum silicon powder, and the material of the second high-temperature fusing agent is different from the material of the second silicon-containing filler.

[0038] In one embodiment of the present application, the reinforcing layer further includes a second lubricant, and the usage amount of the second lubricant is 10-40 wt% of the second silicon-containing filler.

[0039] In one embodiment of the present application, the second lubricant includes one or more combinations of polyamide wax, polyethylene wax, and paraffin wax.

[0040] In one embodiment of the present application, the reinforcing layer further includes a second heat-reflective filler, and the second heat-reflective filler is 5-30 wt% of the second silicon-containing filler.

[0041] In one embodiment of the present application, the second heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium.

[0042] In one embodiment of the present application, the reinforcing layer includes a fiber matrix and a second resin, the reinforcing layer further includes a colorant, and the colorant includes one or more of carbon black, titanium white, iron black, oil-based color concentrate, and transition metal coloring ion oxides.

[0043] In one embodiment of the present application, the heat-resistant protective material further includes a getter, and the getter is filled in the functional layer and / or the reinforcing layer, or the getter is provided between the functional layer and the reinforcing layer to form a getter layer.

[0044] In one embodiment of the present application, the heat-resistant protective material further includes a heat-insulating layer, and the heat-insulating layer is provided on the side away from the reinforcing layer of the functional layer.

[0045] In one embodiment of the present application, the heat-insulating layer includes an aerogel coating or an aerogel felt.

[0046] In order to solve the above technical problems, another technical solution adopted in the present application is to provide a battery including the heat-resistant protective material described in any one of the above embodiments.

[0047] In one embodiment of the present application, the battery includes a battery cell provided with a pressure reducing mechanism on a first wall, and the heat-resistant protective material and the pressure reducing mechanism are provided opposite to each other.

[0048] In one embodiment of the present application, the battery includes a plurality of battery cells including adjacent first battery cells and second battery cells arranged along a first direction, and the heat-resistant protective material is provided between the first battery cell and the second battery cell.

Advantages of the Invention

[0049] The beneficial effects are as follows.

[0050] When receiving a thermal shock, the first resin can carbonize and absorb heat to form a carbon layer that resists heat penetration, and the first filler can increase the integrity of the heat-resistant protective material and enhance the fire flame shock resistance strength.

[0051] A large amount of heat can be absorbed by the melting and vaporization of the silicon-containing filler, and the silicon-containing filler reacts with the carbon layer formed by the first resin to generate solid silicon carbide. The solid silicon carbide can resist high-temperature erosion, high-temperature shear, and tension or compression, effectively enhancing the mechanical properties of the heat-resistant protective material and avoiding the breakthrough of the heat-resistant protective material.

Brief Description of the Drawings

[0052] To more clearly explain the technical solution of the embodiments of the present application, the drawings necessary for describing the embodiments are briefly introduced below. Of course, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

[0053]

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Embodiments for Carrying Out the Invention

[0054] Hereinafter, embodiments of the technical solution of the present application will be described in detail with reference to the drawings. The following embodiments are merely for more clearly explaining the technical solution of the present application, so they are only examples and should not limit the protection scope of the present application.

[0055] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the present application. The terms "comprising", "having" and any variations thereof in the description of the specification, claims and drawings of the present application are intended to cover non-exclusive inclusion.

[0056] In the description of the embodiments of the present application, technical terms such as "first" and "second" are for distinguishing different objects and should not be understood as indicating or implying relative importance, or suggesting the number of technical features shown, a specific order or a primary-secondary relationship. In the description of the embodiments of the present application, unless specifically and clearly limited, "a plurality" means two or more.

[0057] In this specification, when "embodiment" is mentioned, it means that the specific features, structures or characteristics described in accordance with the embodiment may be included in at least one embodiment of the present application. Each occurrence of the term at each position in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive with other embodiments, nor is it an independent or alternative embodiment. One of ordinary skill in the art can clearly or implicitly understand that the embodiments described in this specification can be combined with other embodiments.

[0058] In the description of the embodiments of the present application, the term "and / or" is only used to explain the interrelationship of related objects and indicates that there can be three relationships. For example, A and / or B can indicate three cases: only A exists, both A and B exist at the same time, and only B exists. Also, in this specification, the character " / " generally indicates that the objects related before and after are in an "or" relationship.

[0059] In the description of the embodiments of the present application, the term "a plurality" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of sheets" refers to two or more sheets (including two sheets).

[0060] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal direction", "lateral direction", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "radial direction", "circumferential direction", etc. is the orientation or positional relationship based on the drawings, and is only for the convenience of explaining and simplifying the description of the embodiments of the present application, and does not indicate or imply that the shown devices or components must have a specific orientation and be configured and operated in a specific orientation. Therefore, it should not be understood as limiting the embodiments of the present application.

[0061] In the description of the embodiments of the present application, unless otherwise clearly defined and limited, terms such as "attach", "connect", "couple", "fix", etc. should be understood in a broad sense. For example, it may be a fixed connection, a removable connection, or an integral one, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intervening object, or an internal communication between two elements or an interaction relationship between two elements. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application according to specific situations.

[0062] In the present application, the battery cell can include a lithium metal battery, a sodium metal battery, a magnesium metal battery, etc., but in the embodiments of the present application, it is not limited thereto. The battery cell may have a cylindrical shape, a flat shape, or other shapes, etc., but in the embodiments of the present application, it is not limited thereto. The battery cell is generally classified into three types: cylindrical battery cells, square battery cells, and soft pack battery cells according to the packaging method, and in the embodiments of the present application, it is not limited thereto. In the following embodiments, for the convenience of explanation, a lithium metal battery is taken as an example for explanation.

[0063] The battery referred to in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application can include a battery module or a battery pack, etc. The battery generally includes a housing for packaging one or more battery cells. The housing can avoid liquid or other foreign matters from affecting the charging or discharging of the battery cells.

[0064] In new energy battery vehicles, the battery box as energy is installed in the vehicle, and the battery in the battery box discharges to drive the motor of the new energy vehicle to operate. As the requirements of people for new energy vehicles are gradually increasing, the requirements for the energy density of the battery are also increasing. In the case of a high-energy battery system with a silicon-doped anode, when a single battery or multiple batteries in the battery system undergo thermal runaway, a gas with a temperature > 1500 °C can be generated. When the maximum speed of the gas is greater than the speed of sound, the aerogel-based heat insulation material in the prior art can no longer withstand the temperature shock and air flow shock of such high-temperature and high-speed air flow. Therefore, structural thermal decomposition and mechanical decomposition occur in the aerogel-based heat insulation material, and the protection fails. The high-temperature and high-speed air flow breaks through the housing of the battery pack, and the battery housing made of a steel plate with a melting point of 1500 °C burns directly, burning continuously for about 30 s, directly destroying the new energy vehicle body, and putting the safety of passengers at risk.

[0065] To solve the above problems, the embodiments of the present application provide a technical solution. A heat-resistant protective material is provided in the housing of the battery pack. The heat-resistant protective material can block the high-temperature and high-speed gas-solid mixture generated when the battery undergoes thermal runaway, protect the battery housing from air flow shock and high-temperature melting, and enhance the safety performance of the battery.

[0066] The heat-resistant protective material described in the embodiments of the present application is applicable to batteries and power-consuming devices using the batteries.

[0067] The power-consuming device may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, an aircraft, an electric toy or an electric tool, etc. The vehicle may be a gasoline vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a secondary battery electric vehicle, a hybrid electric vehicle or an extended-range electric vehicle, etc. The aircraft includes airplanes, rockets, space shuttles, spaceships, etc. The electric toy includes fixed or mobile electric toys such as game machines, electric vehicle toys, electric propulsion ship toys and electric airplane toys. The electric tool includes metal cutting electric tools such as electric drills, electric grinders, electric wrenches, electric drivers, electric hammers, electric impact drills, concrete vibrators and electric cutters, grinding electric tools, assembly electric tools and railway electric tools. In the embodiments of the present application, there is no particular limitation on the above power-consuming device.

[0068] In the following embodiments, for the sake of easy explanation, the case where the power-consuming device is a vehicle will be described as an example.

[0069] FIG. 1 is a schematic structural diagram of a vehicle 1 provided according to an embodiment of the present application. As shown in FIG. 1, a battery 2 is provided inside the vehicle 1, and the battery 2 may be provided at the bottom, front or rear of the vehicle 1. The battery 2 can be used to supply power to the vehicle 1. For example, the battery 2 can be used as the operating power source of the vehicle 1.

[0070] FIG. 2 is an exploded schematic diagram of the battery 2 provided according to an embodiment of the present application. As shown in FIG. 2, the battery 2 includes a housing 20, battery cells 6 and a heat-resistant protective material 8. The battery cells 6 and the heat-resistant protective material 8 are housed in the housing 20.

[0071] The housing 20 is used to accommodate the battery cell 6. The housing 20 may have various structures. In some embodiments, the housing 20 can include a first housing part 201 and a second housing part 202. The first housing part 201 and the second housing part 202 cover each other, and the first housing part 201 and the second housing part 202 jointly define a housing space 203 for accommodating the battery cell 6. The second housing part 202 may have a hollow structure that opens on one side. The first housing part 201 has a plate-like structure. The first housing part 201 is joined to the opening side of the second housing part 202 so as to form the housing 20 having the housing space 203. The first housing part 201 and the second housing part 202 may both have a hollow structure that opens on one side, and the opening side of the first housing part 201 is joined to the opening side of the second housing part 202 so as to form the housing 20 having the housing space 203. Of course, the first housing part 201 and the second housing part 202 may have various shapes such as a cylinder or a cuboid.

[0072] In order to enhance the sealing performance after the first housing part 201 and the second housing part 202 are connected, a sealing member such as a sealant or a sealing ring may be provided between the first housing part 201 and the second housing part 202.

[0073] Assuming that the first housing part 201 is joined to the top of the second housing part 202, the first housing part 201 may be called a top cover, and the second housing part 202 may be called a bottom wall.

[0074] In battery 2, there are a plurality of battery cells 6. The plurality of battery cells 6 may be connected in series, in parallel, or in series-parallel. Series-parallel connection means that it includes both series connection and parallel connection of the plurality of battery cells 6. The plurality of battery cells 6 may be directly connected in series, in parallel, or in series-parallel and then the whole formed by the plurality of battery cells 6 may be housed in the housing 20. Of course, first, the plurality of battery cells 6 may be connected in series, in parallel, or in series-parallel to form a battery module (not shown), and then a plurality of battery modules may be connected in series, in parallel, or in series-parallel to form one whole and be housed in the housing 20. The electrical connection between the plurality of battery cells 6 in the battery module can be realized by a bus bar component, thereby realizing the parallel connection, series connection, or series-parallel connection of the plurality of battery cells 6 in the battery module.

[0075] Figure 3 is a schematic structural diagram of the battery cell 6 according to an embodiment of the present application. As shown in Figure 3, the battery cell 6 includes one or more electrode assemblies 61, a case 621, and an end cover 622. The case 621 and the end cover 622 form a housing or a battery box 62. The wall of the case 621 and the end cover 622 are both called the wall of the battery cell 6. In the case of a rectangular parallelepiped-shaped battery cell 6, the wall of the case 621 includes a bottom wall and four side walls. The case 621 is determined according to the shape after combining one or more electrode assemblies 61. For example, the case 621 may be a hollow rectangular parallelepiped, a cube, or a cylinder, and one surface of the case 621 has an opening so that one or more electrode assemblies 61 can be placed in the case 621. For example, when the case 621 is a hollow rectangular parallelepiped or a cube, one plane of the case 621 is an opening surface, that is, the plane communicates the inside and outside of the case 621 by not having a wall body. When the case 621 is a hollow cylinder, the end face of the case 621 is an opening surface, that is, the end face communicates the inside and outside of the case 621 by not having a wall body. The end cover 622 covers the opening and is connected to the case 621 so as to form a sealed cavity for placing the electrode assembly 61. The case 621 is filled with an electrolyte, for example, an electrolyte solution.

[0076] The battery cell 6 may further include two electrode terminals 63, and the two electrode terminals 63 may be provided on the end cover 622. The end cover 622 is usually in a flat plate shape, and the two electrode terminals 63 are fixed to the flat plate surface of the end cover 622. The two electrode terminals 63 are a positive electrode terminal 631 and a negative electrode terminal 632 respectively. For each electrode terminal 63, one connection member 64 is correspondingly provided. This connection member 64 may also be called a current collecting member 64. It is located between the end cover 622 and the electrode assembly 61 and is used to realize the electrical connection between the electrode assembly 61 and the electrode terminal 63.

[0077] In this battery cell 6, according to the actual usage needs, one electrode assembly 61 may be provided, or a plurality of electrode assemblies 61 may be provided. As shown in FIG. 3, four independent electrode assemblies 61 are provided in the battery cell 6.

[0078] The battery cell 6 may further be provided with a pressure reducing mechanism 65. The pressure reducing mechanism 65 is used to operate and release the internal pressure or temperature when the internal pressure or temperature of the battery cell 6 reaches a threshold value.

[0079] FIG. 4 is an exploded structural schematic diagram of a battery according to another embodiment of the present application. As shown in FIG. 4, the battery 2 includes a battery cell 6 and a heat-resistant protective material 8. A pressure reducing mechanism 65 is provided on the first wall of the battery cell 6, and the heat-resistant protective material 8 and the pressure reducing mechanism 65 are provided opposite to each other.

[0080] In the embodiment of the present application, the pressure reducing mechanism 65 is a structural component for operating and releasing the internal pressure of the battery cell 6 when the internal pressure or temperature of the battery cell 6 reaches a threshold value. For example, the pressure reducing mechanism 65 may be a temperature-sensitive pressure reducing mechanism arranged to be melted when the internal temperature of the battery cell 6 provided with the pressure reducing mechanism 65 reaches a threshold value, and / or the pressure reducing mechanism 65 may be a pressure-sensitive pressure reducing mechanism arranged to burst when the internal air pressure of the battery cell 6 provided with the pressure reducing mechanism 65 reaches a threshold value. In the present application, the type of the pressure reducing mechanism is not limited at all.

[0081] The battery 2 includes battery cells 6, and a pressure relief mechanism 65 for protecting the battery cells 6 is provided on the first wall of the battery cells 6. The battery 2 further includes a heat-resistant protective material 8, and the heat-resistant protective material 8 and the pressure relief mechanism 65 are provided opposite to each other, that is, the heat-resistant protective material 8 faces the pressure relief mechanism 65.

[0082] In the above technical solution, by providing the pressure relief mechanism 65 and the heat-resistant protective material 8 opposite to each other, when a thermal runaway occurs inside the battery cell 6, the heat-resistant protective material 8 made of polymer matrix composite fiber can block the high-temperature and high-speed gas-solid mixture released by the pressure relief mechanism 65, protect the battery case from air flow impact and high-temperature melting, and ensure the safety of the battery 2.

[0083] In the above technical solution, a fiber-reinforced resin composite board is manufactured using the resin in the polymer material as a matrix to serve as the heat-resistant protective material 8. Compared with other polymer material matrices, both the high-temperature resistance performance and the impact resistance performance of the fiber-reinforced resin composite board are good.

[0084] Optionally, as shown in FIG. 4, the battery cell 6 is housed in a housing 20, and the first wall is a wall of the battery cell 6 that is close to and faces the top cover 201 of the housing 20.

[0085] When the first wall is a wall of the battery cell 6 that is close to and faces the top cover 201 of the housing 20, the pressure relief mechanism 65 is close to and faces the top cover 201.

[0086] In the above technical solution, the heat-resistant protective material 8 is provided between the pressure relief mechanism 65 and the top cover 201. When the battery cell 6 has a thermal runaway and the pressure relief mechanism 65 releases the temperature and pressure inside the battery cell 6, the heat-resistant protective material 8 made of polymer matrix composite fiber can block the high-temperature and high-speed gas-solid mixture released by the pressure relief mechanism 65, protect the top cover 201 of the battery 2 from air flow impact and high-temperature melting, and further protect the safety of the battery 2.

[0087] FIG. 5 is a schematic diagram of a half-sectional structure of a battery housing according to an embodiment of the present application. As shown in FIG. 5, optionally, the heat-resistant protective material 8 and the top cover 201 are integrally provided.

[0088] The heat-resistant protective material 8 and the top cover 201 are integrally provided, for example, attached to the surface of the top cover 201 as a patch. That is, both the heat-resistant protective material 8 and the top cover 201 may be the top cover 201 of the battery 2. As shown in FIG. 5, the heat-resistant protective material 8 may be the top cover 201 of the battery 2 alone.

[0089] In the above technical solution, when both the heat-resistant protective material 8 and the top cover 201 are the top cover 201 of the battery 2, the top cover 201 of the battery 2 has a two-layer structure. The heat-resistant protective material 8 protects the top cover 201 and further preferably protects the safety of the battery 2. When the heat-resistant protective material 8 is the top cover 201 of the battery 2 alone, the heat-resistant protective material 8 can not only keep the top cover 201 of the battery 2 from being affected by high temperature and airflow impact, but also simplify the structure of the battery 2 and reduce the production cost of the battery 2.

[0090] FIG. 6 is a schematic diagram of a top cover according to an embodiment of the present application. As shown in FIG. 6, when the heat-resistant protective material 8 and the top cover 201 are integrally provided, the top cover 201 may have an irregular shape. In the embodiment of the present application, the top cover 201 may be square, circular, etc., and the present application does not limit this at all. That is, in the production process, according to the needs of specific products, the top cover 201 and the heat-resistant protective material 8 of any shape can be manufactured.

[0091] Optionally, as shown in FIG. 4, the heat-resistant protective material 8 is provided between the top cover 201 and the first wall.

[0092] The heat-resistant protective material 8 is provided between the top cover 201 and the first wall. That is, the pressure reducing mechanism 65 faces the top cover 201, and the heat-resistant protective material 8 is provided between the top cover 201 and the pressure reducing mechanism 65.

[0093] In the above technical solution, a heat-resistant protective material 8 is provided between the top cover 201 and the pressure reduction structure 65, and the pressure reduction mechanism 65 faces the top cover 201. In this way, by directly protecting the top cover 201, the heat-resistant protective material 8 can prevent the top cover 201 facing the pressure reduction mechanism 65 from being affected by high temperature and air flow impact, and can guarantee the safety of the battery 2.

[0094] Continuing to refer to FIG. 4, optionally, the sizes of the heat-resistant protective material 8 and the top cover 201 are the same.

[0095] By providing the heat-resistant protective material 8 between the top cover 201 and the pressure reduction structure 65 and making the sizes of the heat-resistant protective material 8 and the top cover 201 the same, the heat-resistant protective material 8 can more comprehensively protect the top cover 201.

[0096] In the above technical solution, by providing the heat-resistant protective material 8 between the top cover 201 and the pressure reduction structure 65 and making the sizes of the heat-resistant protective material 8 and the top cover 201 the same, the heat-resistant protective material 8 can not only more comprehensively protect the top cover 201 and prevent the top cover 201 from being hit by the high-temperature and high-speed gas-solid mixture released by the pressure reduction mechanism 65, but also enhance the sealing effect on the inside of the battery 2. In addition, the fact that the sizes of the heat-resistant protective material 8 and the top cover 201 are the same also contributes to assembly and reduces the difficulty of assembly.

[0097] FIG. 7 is an exploded structural schematic diagram of a battery according to a further embodiment of the present application. As shown in FIG. 7, optionally, the size of the heat-resistant protective material 8 is smaller than that of the top cover 201.

[0098] In the above technical solution, the heat-resistant protective material 8 is provided between the top cover 201 and the first wall where the pressure reduction mechanism 65 is provided. When the size of the heat-resistant protective material 8 is smaller than that of the top cover 201, the heat-resistant protective material 8 can protect the top cover 201 and improve the safety performance of the battery 2, while also reducing production costs.

[0099] FIG. 8 is a schematic exploded view of a battery according to a further embodiment of the present application. As shown in FIG. 8, optionally, the heat-resistant protective material 8 is a strip-shaped plate, and the projection of the heat-resistant protective material 8 on the first wall covers the pressure reducing mechanism 65.

[0100] The shape of the heat-resistant protective material 8 may be strip-shaped as shown in FIG. 8, or may be circular or any other arbitrary shape, as long as the projection of the heat-resistant protective material 8 on the first wall covers the pressure reducing mechanism 65 and can perform the function of protecting the housing of the battery 2. In the present application, there is no limitation on the shape of the heat-resistant protective material 8.

[0101] In the above technical solution, the heat-resistant protective material 8 is provided between the top cover 201 and the first wall. When the heat-resistant protective material 8 is strip-shaped and the projection on the first wall covers the pressure reducing mechanism 65, the heat-resistant protective material 8 can maintain a good protective effect on the top cover 201, while maximizing cost reduction and avoiding waste of materials in the non-protected area.

[0102] Optionally, the heat-resistant protective material 8 and the top cover 201 are connected by bolts or adhesives.

[0103] The connection form between the heat-resistant protective material 8 and the top cover 201 is various, as long as the fixation of the two can be achieved. In the present application, there is no limitation on this. However, in the actual production process, selecting a convenient and highly operable connection form contributes to wide popularization in actual applications.

[0104] In the above technical solution, the connection between the heat-resistant protective material 8 and the top cover 201 is realized by bolts or adhesives. This connection form is easy to realize, highly operable, and contributes to wide application in production.

[0105] FIG. 9 is a schematic structural view of the bottom wall of a battery according to an embodiment of the present application. As shown in FIG. 9, optionally, the battery cell 6 is housed in the housing 20, and the first wall is a wall provided near the bottom wall 202 of the housing 20 and facing the bottom wall 202 of the battery cell 6.

[0106] When the first wall is a wall provided near and facing the bottom wall 202 of the housing 20 of the battery cell 6, the pressure reducing mechanism 65 faces near and toward the bottom wall 202.

[0107] In the above technical solution, the heat-resistant protective material 8 is provided between the pressure reducing mechanism 65 and the bottom wall 202. When the battery cell 6 undergoes thermal runaway and the pressure reducing mechanism 65 releases the temperature and pressure inside the battery cell 6, the heat-resistant protective material 8 made of polymer matrix composite fiber blocks the high-temperature and high-speed gas-solid mixture released by the pressure reducing mechanism 65, protects the bottom wall 202 of the battery 2 from airflow impact and high-temperature melting, and can further protect the safety of the battery 2.

[0108] FIG. 10 is a schematic half-sectional structure diagram of a battery housing according to another embodiment of the present application. As shown in FIG. 10, optionally, the heat-resistant protective material 8 and the bottom wall 202 are integrally provided.

[0109] The heat-resistant protective material 8 and the bottom wall 202 are integrally provided, that is, the heat-resistant protective material 8 and the bottom wall 202 may both be the bottom wall 202 of the battery 2, or the heat-resistant protective material 8 may be the bottom wall 202 of the battery 2 alone as shown in FIG. 10.

[0110] In the above technical solution, when the heat-resistant protective material 8 and the bottom wall 202 together form the bottom wall 202 of the battery 2, the bottom wall 202 of the battery 2 has a two-layer structure, and the heat-resistant protective material 8 protects the bottom wall 202 and further preferably protects the safety of the battery 2. When the heat-resistant protective material 8 alone forms the bottom wall 202 of the battery 2, the heat-resistant protective material 8 can not only keep the bottom wall 202 of the battery 2 from being affected by high temperature and airflow impact, but also simplify the structure of the battery 2 and reduce the production cost of the battery 2.

[0111] When the pressure relief mechanism 65 inside the battery 2 faces only the top cover 201, the heat-resistant protective material 8 and the top cover 201 are provided integrally to protect the safety of the battery 2. When the pressure relief mechanism 65 faces only the bottom wall 202, the heat-resistant protective material 8 and the bottom wall 202 are provided integrally to protect the safety of the battery 2. When the pressure relief mechanism 65 inside the battery 2 may face the top cover 201 or may face the bottom wall 202, as shown in FIG. 10, the heat-resistant protective material 8 can be provided on either the top cover 201 or the bottom wall 202. In the present application, the installation of the heat-resistant protective material 8 in the battery 2 is not specifically limited. It is only necessary that the heat-resistant protective material 8 exists on the wall facing the pressure relief mechanism 65 of the battery cell 6 in the battery 2. That is, the heat-resistant protective material 8 may be the top cover 201, the bottom wall 202, or the side wall. Further, the heat-resistant protective material 8 may be a beam in the battery 2. The specific position of the heat-resistant protective material 8 can change according to the arrangement position of the battery cells 6 in the battery 2 and can also be provided at any position in the battery 2 according to actual application needs.

[0112] Optionally, as shown in FIG. 9, the heat-resistant protective material 8 is provided between the bottom wall 202 and the first wall.

[0113] The heat-resistant protective material 8 is provided between the bottom wall 202 and the first wall. That is, the pressure relief mechanism 65 faces the bottom wall 202, and the heat-resistant protective material 8 is provided between the bottom wall 202 and the pressure relief mechanism 65.

[0114] In the above technical solution, the heat-resistant protective material 8 is provided between the bottom wall 202 and the pressure relief structure 65, and the pressure relief mechanism 65 faces the top cover 201. In this way, by directly protecting the bottom wall 202, the heat-resistant protective material 8 can prevent the bottom wall 202 facing the pressure relief mechanism 65 from being affected by high temperature and air flow impact, and can guarantee the safety of the battery 2.

[0115] Optionally, as shown in FIG. 9, a heat management component 66 is provided between the heat-resistant protective material 8 and the first wall. The heat management component 66 is used to contain a fluid to adjust the temperature of the battery cell 6.

[0116] The thermal management component 66 is used to contain a fluid and regulate the temperature of the battery cell 6. This fluid may be a liquid or a gas, and regulating the temperature means heating or cooling the battery cell 6. When cooling or reducing the temperature of the battery cell 6, the thermal management component 66 is used to contain a cooling fluid and lower the temperature of the battery cell 6. In this case, the thermal management component 66 may be called a cooling component, a cooling system, a cooling plate, etc., and the fluid contained therein may be called a cooling medium or a cooling fluid, and more specifically, it may be called a coolant or a cooling gas. Also, the thermal management component 66 may be used to heat and raise the temperature of the battery cell 6, and the embodiments of the present application are not limited thereto. Optionally, the fluid may circulate and flow to achieve a better temperature regulation effect. Optionally, the fluid may be water, a mixture of water and ethylene glycol, air, etc.

[0117] In the above technical solution, the heat-resistant protective material 8 is provided between the first wall and the housing of the battery 2, or the heat-resistant protective material 8 is directly the housing of the battery 2, thereby protecting the housing of the battery 2 from high temperature and the impact of the air flow, and further protecting the safety of the battery 2. By providing a thermal management component for regulating the temperature of the battery cell 6 between the first wall and the heat-resistant protective material 8, the temperature of the battery cell 6 can be regulated so that the battery cell 6 operates normally according to the needs of the battery cell 6.

[0118] Optionally, a fragile area 661 is provided opposite to the pressure reducing mechanism 65 in the thermal management component 66. The fragile area 661 is arranged such that when the pressure reducing mechanism 65 operates, the discharge can be broken by the discharge of the battery cell 6 in order for the discharge to pass through the fragile area 661.

[0119] The fragile area 661 can adopt various installations that are easily broken by the discharge, and the embodiments of the present application are not limited thereto at all.

[0120] In the heat management component 66, a flow path for the fluid can be formed with a heat conductive material. The fluid flows through the flow path and conducts heat through the heat conductive material, thereby adjusting the temperature of the battery cell 6. In the embodiment of the present application, in the vulnerable area 661, there may be only the heat conductive material without fluid, and a thin heat conductive material layer has already been formed and is easily damaged by the discharge. For example, the side close to the bottom wall 202 of the vulnerable area 661 may be a heat conductive material layer so as to form the vulnerable area 661.

[0121] In the above technical solution, the heat-resistant protective material 8 is provided between the first wall and the housing of the battery 2, or the heat-resistant protective material 8 is directly used as the housing of the battery 2, and the safety of the battery 2 can be protected. By providing the heat management component 66 between the first wall and the heat-resistant protective material 8, the temperature of the battery cell 6 can be adjusted according to the actual needs of the battery cell 6, and the normal function of the battery cell 6 can be guaranteed. By providing the vulnerable area 661 in the heat management component 66, when the vulnerable area 661 is destroyed by airflow impact or high temperature, the discharge can pass through the vulnerable area 661 and be quickly discharged away from the battery cell 6, the danger of the discharge to the battery 2 is reduced, and the safety performance of the battery 2 is further improved.

[0122] FIG. 11 is an exploded structural schematic diagram of the bottom wall of the battery according to another embodiment of the present application. As shown in FIG. 11, in an embodiment of the present application, a heat insulation component 67 is provided between the heat-resistant protective material 8 and the housing 20.

[0123] In the above technical solution, by adding the heat-resistant protective material 8 between the first wall provided with the pressure reduction mechanism 65 and the housing 20, the housing 20 of the battery 2 can be protected from high temperature and high-speed airflow impact. By further providing the heat insulation component 67 between the heat-resistant protective material 8 and the housing 20, the temperature of the housing 20 can be further reduced, and the safety of the battery 2 can be protected.

[0124] Optionally, the heat insulation component 67 is an air sandwich layer.

[0125] The addition of the heat insulation component 67 is for further reducing the temperature of the housing 20. By adopting the air sandwich layer as the heat insulation component 67, the heat inside the battery 2 transmitted to the housing 20 is significantly reduced, and the heat insulation effect is very obvious.

[0126] In the above technical solution, by providing the air sandwich layer as the heat insulation component 67 between the heat-resistant protective material 8 and the housing 20, the temperature of the housing 20 can be further reduced, and the safety performance of the battery 2 can be enhanced.

[0127] FIG. 12 shows a schematic structural diagram of the battery 2 according to an embodiment of the present application. As shown in FIG. 12, the battery 2 includes a plurality of battery cells 6, the plurality of battery cells 6 includes an adjacent first battery cell 6a and a second battery cell 6b, the first battery cell 6a and the second battery cell 6b are arranged along the first direction x, the battery 2 further includes a heat-resistant protective material 8, and the heat-resistant protective material 8 is provided between the first battery cell 6a and the second battery cell 6b.

[0128] When a heat-resistant protective material 8 is provided between the first battery cell 6a and the second battery cell 6b and some battery cells 6 in the battery 2 have a thermal runaway, the heat-resistant protective material 8 prevents the thermally runaway battery cell 6 from transmitting heat to the adjacent battery cell 6, thereby avoiding the spread of thermal runaway and effectively preventing the spread of thermal runaway in the battery 2, and enhancing the safety of the battery 2.

[0129] In the embodiment of the present application, as shown in FIG. 13, the heat-resistant protective material 8 is provided between the first wall 68 of the first battery cell 6a and the second wall 69 of the second battery cell 6b. The first wall 68 is the wall with the largest surface area among the walls of the first battery cell 6a, and the second wall 69 is the wall with the largest surface area in the second battery cell 6b.

[0130] The heat-resistant protective material 8 is provided between the walls with the largest surface areas of two adjacent battery cells 6. In this way, the heat-resistant protective material 8 prevents the spread range of the thermal runaway of the battery cell 6 from becoming larger, and further contributes to preventing the spread of thermal runaway in the battery 2.

[0131] It should be understood that the heat-resistant protective material 8 may be provided between the other walls of two adjacent battery cells 6. When there are battery cells 6 adjacent to any of the four circumferences of one battery cell 6, heat-resistant protective materials 8 facing the side walls may be provided on any of the four side walls, and it may be provided according to the arrangement status of the battery cells 6 in the battery 2 and the needs of the space, and the present application does not limit this.

[0132] As shown in FIG. 14, two heat-resistant protective materials 8 are provided between the first battery cell 6a and the second battery cell 6b, and a heat resistance layer 9 is sandwiched between the two heat-resistant protective materials 8. By providing the heat resistance layer 9 between the two heat-resistant protective materials 8 to form a "sandwich" structure, the heat-resistant protective material 8 protects the heat resistance layer 9 from being deformed by being pressed by the battery cells 6a and 6b, enables the heat resistance layer 9 to better exert its heat insulation effect, and can ensure that the heat resistance layer 9 effectively blocks the spread of thermal runaway in the battery 2. Specifically, the heat resistance layer 9 can employ an aerogel felt. It is understood that the heat-resistant protective material 8 of the present application may be provided at any location in the battery that requires heat protection, and the above embodiment is merely described as an example.

[0133] Referring to FIG. 15, some embodiments of the present application provide a heat-resistant protective material 8, the heat-resistant protective material 8 includes a composite layer, the composite layer includes a fiber matrix 810 and a resin 811, and the resin 811 is dispersed in the voids of the fiber matrix 810 and / or on the surface of the fiber matrix 810. That is, the heat-resistant protective material 8 includes a fiber resin (FR) composite layer 81.

[0134] The shape and size of the heat-resistant protective material 8 provided by the present application are not limited, and the present application only describes the plate-shaped heat-resistant protective material as an example. The heat-resistant protective material 8 of the present application may be provided opposite to the pressure reduction mechanism in the battery cell, may be provided between different battery cells, and the heat-resistant protective material 8 may be directly manufactured as the upper cover or the lower cover of the battery cell or the battery pack.

[0135] The fiber matrix 810 provides high-temperature mechanical properties and can resist the impact of high-temperature particles and airflows. The continuous fiber matrix 810 has excellent mechanical strength and impact toughness. During the thermal shock process, the solid slag inside the cell is ejected along with the heat flow and blocked by the fiber matrix 810. It utilizes its own deformation to absorb the impact force of the flame heat flow. The slag continuously adheres to the fiber matrix 810 to form a barrier and further resist the heat flow shock. The volume ratio of the fiber matrix 810 in the composite layer is 50% - 75%, for example, 50%, 55%, 60%, 65%, 70% or 75%, etc. It is understood that the higher the content of the fiber matrix 810, the more the strength and toughness of the heat-resistant protective material 8 can be guaranteed. When the volume ratio of the fiber matrix 810 in the composite layer is less than 50%, the strength and toughness of the heat-resistant protective material 8 decrease. When the volume ratio of the fiber matrix 810 in the composite layer is greater than 75%, it is difficult to disperse the resin 811 inside the voids of the entire fiber matrix 810 and / or on the surface of the fiber matrix 810 to form a composite structure with strong bonding force.

[0136] The fibers of the fiber matrix 810 include one or more of carbon fibers, silicon carbide fibers, silicon nitride fibers, quartz fibers, aluminum silicate fibers, asbestos fibers, high-silica fibers, boron-carbon fibers, carbon nanotubes, and can effectively resist thermal shock. In some embodiments, the fiber matrix 810 includes a fiber cloth and / or a fiber felt. The fiber cloth is a woven fabric of long fibers and may be one or more of a fiber twill fabric, a fiber satin fabric, a fiber uniaxial fabric, and a fiber multi-axial fabric. The fiber felt is a flaky product manufactured by bonding long fibers or chopped fibers without directionality by a chemical adhesive or a mechanical action. The long fibers are continuous protofilaments, and the chopped fibers are products obtained by chopping continuous protofilaments. The long fibers and the chopped fibers are relative concepts, and the specific size can be selected according to the size of the fiber matrix 810.

[0137] In some embodiments, the fiber cloth and / or fiber felt in the fiber matrix 810 may be one layer or multiple layers. In one specific embodiment, the fiber matrix 810 includes fiber cloth and / or fiber felt provided in a stacked manner, for example, a plurality of fiber cloths provided in a stacked manner, a plurality of fiber felts provided in a stacked manner, or fiber cloth and fiber felt provided in a stacked manner. Two or more layers of fiber cloth and / or fiber felt can be adhered and cured by the resin 811 after being stacked.

[0138] The resin 811 is dispersed in the voids of the fiber matrix 810 and / or covers the upper and lower surfaces of the fiber matrix 810. The composite form of the fiber matrix 810 and the resin 811 is not limited. Specifically, by immersing the fiber cloth and / or fiber felt in the resin 811 and then curing to form a composite layer, the resin 811 can be dispersed in the voids of the fiber matrix 810 and / or cured on the upper and lower surfaces of the fiber matrix 810. It is understood that a composite layer may also be formed by laminating the fiber cloth and / or fiber felt and the sheet-like resin 811 and then performing hot pressing. When subjected to a thermal shock, the resin 811 can carbonize and absorb heat to form a carbon layer that resists heat penetration. The resin 811 includes one or a combination of multiple of phenol resin, benzoxazine resin, furan resin, polyurea, and phenol-modified epoxy resin. The furan resin includes furfural acetone resin. The carbon content of the resin 811 is high. The resin 811 has a high decomposition temperature and can absorb more heat by decomposing and carbonizing, and can exert an effect of resisting thermal shock. In some specific embodiments of the present application, the mass content of the carbon element in the resin 811 is greater than 40%, preferably the mass content of the carbon element in the resin 811 is greater than 50%.

[0139] In some embodiments, the composite form of the fiber matrix 810 and the resin 811 is not limited. Specifically, a plurality of layers of fiber cloth are immersed in the resin 811 and then laminated. As the curing conditions, first, compression molding is performed, the compression molding temperature is 130 - 150 °C, the compression molding time is 20 - 40 min, and then it is placed in an oven, the baking temperature is 120 - 180 °C, and the baking time is 1 - 4 h. In another form, first, the prefabricated heat-resistant protective material 8 is semi-cured and then cured. Specifically, after a plurality of layers of fiber cloth are immersed in the resin 811, they are each left standing at 25 °C until the surface is dry (semi-cured), or compression molded at 50 - 80 °C for 10 - 40 min / dried in an oven until the surface is dry (semi-cured). Then, the semi-cured heat-resistant protective material prefabricated parts are laminated and cured. As the curing conditions, first, compression molding is performed, the compression molding temperature is 130 - 160 °C, the compression molding time is 10 - 40 min, and then it is placed in an oven, the baking temperature is 150 - 200 °C, and the baking time is 1 - 4 h.

[0140] Furthermore, in some embodiments, a viscosity modifier is dispersed in the resin 811. The viscosity modifier includes one or a combination of methanol, ethanol, ethyl acetate, acetone, and butanone, and is used to reduce the viscosity of the resin 811, making it easier for the resin 811 to infiltrate and penetrate the fibers and facilitating the production and processing of a product with a uniform thickness. Reducing the viscosity of the resin 811 contributes to adding a filler 842, which is a functional material such as silicon-containing particles or chopped fibers. The usage amount of the viscosity modifier is 1 - 10% of the volume of the resin 811, for example, 1%, 3%, 5%, 7%, or 10%, etc. When the usage amount of the viscosity modifier is lower than 1%, the viscosity of the resin 811 is high, the fluidity is low, and it is difficult to form a product with a uniform thickness. When the usage amount of the viscosity modifier is higher than 10%, the viscosity of the resin 811 is low, the fluidity is high, and during the processing and molding process of the composition, the solvent of the resin 811 volatilizes and air bubble defects are formed in the product. Also, in some embodiments, when it is necessary to increase the viscosity of the resin 811, usually, a means of heating the resin 811 to volatilize the solvent in the resin 811 before the resin 811 is combined with the fiber matrix 810 is adopted.

[0141] Optionally, in some embodiments, a curing agent may be dispersed in the resin 811. The curing agent can effectively shorten the curing time of the resin 811 and contribute to the mass production or batch production of the heat-resistant protective material 8. For example, the curing agent used for phenolic resin is hexamethylenetetramine, and the usage amount of hexamethylenetetramine is 2.5% - 3% of the mass of the phenolic resin. The curing agent used for furfural acetone resin is a phosphoric acid curing agent, and the usage amount of the phosphoric acid curing agent is 6% - 7% of the mass of the furfural acetone resin. In some other embodiments, no curing agent is used for benzoxazine resin, furan resin, and polyurea.

[0142] Optionally, in some embodiments, a flame retardant for preventing the combustion of the heat-resistant protective material 8 may be further dispersed in the resin 811. The flame retardant can include one or more of ammonium polyphosphate, aluminum hydroxide, and DOPO. The usage amount of the flame retardant is 5% - 40% of the mass of the resin 811, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40%, etc.

[0143] In some embodiments, a phase change material is dispersed in the resin 811. The usage amount of the phase change material is 5% - 20% of the volume of the fiber matrix 810, for example, 5%, 10%, 15%, or 20%, etc. The phase change material can absorb heat to provide resistance to thermal shock and can also reduce heat transfer from the heated surface to the unheated surface. Specifically, the phase change material can adopt hydrated salt components such as sodium sulfate decahydrate (Na 2 SO 4 ·10H 2 O), calcium chloride hexahydrate (CaCl 2 ·6H 2 O), and magnesium chloride hexahydrate (MgCl 2 ·6H 2 O).

[0144] In some embodiments, the heat-resistant protective material 8 further includes a ceramic precursor. Under the action of thermal shock, the ceramic precursor can generate a ceramic material such as SiCN and / or SiCNO, thereby increasing the temperature resistance and flame impact resistance of the heat-resistant protective material 8. The ceramic precursor can include one or more of polysilazane resin, polyborosilazane resin, and polycarbosilane resin. While the bending strength of the heat-resistant protective material at room temperature is reduced by the ceramic precursor, the ceramic precursor reacts at high temperature to generate a ceramic material, and does not reduce the temperature resistance and flame impact resistance of the heat-resistant protective material 8. In one embodiment, the volume ratio of the ceramic precursor to the sum of the volumes of the ceramic precursor and the resin 811 is less than 50%, or the mass ratio of the ceramic precursor to the sum of the masses of the ceramic precursor and the resin 811 is less than 50%, thereby ensuring that the heat-resistant protective material has excellent bending strength at room temperature, controlling the cost of the heat-resistant protective material 8, increasing the temperature resistance and flame impact resistance of the heat-resistant protective material 8, and maintaining the market competitiveness of the heat-resistant protective material 8.

[0145] The means for adding the ceramic precursor to the heat-resistant protective material 8 is not limited, and the ceramic precursor and the resin 811 can be dispersed together in the voids between the fiber matrix 810 and / or cover the upper and lower surfaces of the fiber matrix 810 therewith. The ceramic precursor can be directly provided on the surface of the fiber resin composite layer 81, or can be provided by laminating with the fiber resin composite layer 81 after the ceramic precursor and the fiber matrix 810 are compounded.

[0146] In some embodiments, the fiber matrix 810 can include a first fiber matrix and a second fiber matrix. The resin 811 can be dispersed within the voids of the first fiber matrix and / or cover two opposing surfaces of the first fiber matrix to form a first composite layer. The ceramic precursor can be dispersed within the voids of the second fiber matrix and / or cover two opposing surfaces of the second fiber matrix to form a second composite layer. The first composite layer and the second composite layer are provided in a stacked manner to form a stacked structure. In one specific embodiment, two first composite layers sandwich at least one second composite layer to form a stacked structure. In another specific embodiment, two second composite layers sandwich at least one first composite layer to form a stacked structure. In another specific embodiment, a plurality of first composite layers and a plurality of second composite layers are provided in an alternating stacked manner.

[0147] In some embodiments, a mixture of the resin 811 and the ceramic precursor slurry is dispersed within the voids of the fiber matrix 810 and / or covers two opposing surfaces of the fiber matrix 810 by impregnation and curing. For example, polysilazane is used as the ceramic precursor slurry. The resin 811 and polysilazane are mixed, and a fiber cloth is employed to be impregnated in the mixed solution of the resin 811 and polysilazane. As for the curing conditions, first, it is compression molded at 50 - 80°C for 20 - 40 minutes, then the temperature is raised to 130 - 150°C and maintained for 20 - 40 minutes, and then it is placed in an oven and maintained at 150 - 180°C for 1 - 2 hours until it is completely cured. In some other embodiments, the ceramic precursor is applied to one surface of the composite layer or two opposing surfaces of the composite layer in the form of a slurry.

[0148] In some embodiments, referring to FIG. 16, the heat-resistant protective material 8 further includes a filler 842. The filler 842 can include one or more of a silicon-containing filler, a high-temperature fusing agent, a lubricant, and a heat-reflective filler.

[0149] The silicon-containing filler may be applied to the surface of the composite layer or embedded in the resin 811. For example, first spray the silicon-containing filler on the surface of the composite layer, and then embed the silicon-containing filler in the resin 811 by hot pressing. For example, first set the hot pressing temperature to 120°C to 160°C, the hot pressing time to 20 min to 40 min, bake at 130°C to 180°C for 1 h to 3 h after hot pressing, or disperse the silicon-containing filler in the resin 811 and infiltrate with the resin in which the silicon-containing filler is dispersed. The amount of the silicon-containing filler used is 40 to 70% of the volume of the composite layer. Usually, under the action of 1200°C, the silicon-containing filler can start to melt at high temperature and can absorb a large amount of heat by the vaporization of the silicon-containing filler. When the silicon-containing filler starts to melt, it reacts with the carbon layer formed by the resin 811 to generate solid silicon carbide. The solid silicon carbide can resist high-temperature erosion, high-temperature shear, and tension or compression, effectively enhancing the mechanical properties of the heat-resistant protective material 8 and avoiding the breakthrough of the heat-resistant protective material 8.

[0150] In some embodiments, the silicon-containing filler includes one or a combination of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, and talc. The quartz powder includes silica fine powder. In one specific embodiment, the silicon-containing filler includes silica aerogel powder and mica powder, and the mass ratio of silica aerogel powder to mica powder is 1:3 to 1:1. Silica aerogel is a porous material with mesopores and has an extremely low thermal conductivity. When the heat-resistant protective material 8 is subjected to a thermal shock, the temperature of the heat-receiving surface of the heat-resistant protective material 8 rapidly rises to form a steep temperature gradient, and the silica aerogel can delay the heat transfer from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8. The silica aerogel powder is prone to shrinkage of the pore structure under the action of high temperature of 800°C to 1000°C, and the heat transfer delay effect from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8 becomes weak. Using mica powder in combination with silica aerogel, mica has excellent heat resistance and heat insulation properties. Mica becomes brittle at 800°C to 1000°C, but its structure is not destroyed and it can still maintain its heat insulation performance. At 1050°C to 1100°C, the mica structure is destroyed. After the temperature of the heat-receiving surface of the heat-resistant protective material 8 rises to 1200°C, silicon begins to melt, reacts with the resin carbon layer to form porous solid silicon carbide, resists thermal shock, reduces heat transfer from the heat-receiving surface to the non-heat-receiving surface, and this process absorbs heat to remove a large amount of heat and can further resist thermal shock.

[0151] In some other embodiments, the silicon-containing filler includes silica and aluminum oxide. Aluminum oxide can enhance the temperature resistance of silica. Under the action of high temperature of thermal shock, silica can react with the carbon layer formed by carbonization of the resin to form silicon carbide. The usage amount of silica is 50 to 80 wt% of the silicon-containing filler, and the usage amount of aluminum oxide is 10 to 30 wt% of the silicon-containing filler.

[0152] In some embodiments, the filler 842 is a high-temperature fusing agent, that is, the heat-resistant protective material 8 further includes a high-temperature fusing agent, and the high-temperature fusing agent has a low melting point and helps to form a carbon layer formed by the melting or vaporization of the silicon-containing filler and the carbonization of the resin 811 and solid silicon carbide. The usage amount of the high-temperature fusing agent is 40% to 70% of the volume of the fiber matrix 810, and the high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, and aluminum silicon powder. Talc may be further used as a lubricant and helps in the molding of the composition. In some embodiments, the high-temperature fusing agent is applied to the surface of the composite layer or dispersed in the resin 811. For example, first spray the high-temperature fusing agent on the surface of the composite layer, and then embed the high-temperature fusing agent into the resin 811 by hot pressing, or disperse the high-temperature fusing agent in the resin 811, and infiltrate the fiber matrix 810 with the resin 811 in which the high-temperature fusing agent is dispersed.

[0153] In embodiments including a silicon-containing filler, the filler 842 further includes a high-temperature fusing agent. That is, the heat-resistant protective material 8 includes a silicon-containing filler and a high-temperature fusing agent, and the usage amount of the high-temperature fusing agent is 10 wt% to 40 wt% of the silicon-containing filler, such as 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt% or 40 wt% and so on. The high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, and aluminum silicon powder. It should be noted that the material of the high-temperature fusing agent is different from the material of the silicon-containing filler. In some embodiments, the high-temperature fusing agent is applied to the surface of the composite layer or dispersed in the resin 811. For example, first mix the silicon-containing filler and the high-temperature fusing agent and spray them on the surface of the composite layer, or spray them in sequence, and then embed the silicon-containing filler and the high-temperature fusing agent into the resin 811 by hot pressing. For example, first set the hot pressing temperature to 120°C to 160°C, the hot pressing time to 20 min to 40 min, bake at 130°C to 180°C for 1 h to 3 h after hot pressing, or disperse both the silicon-containing filler and the high-temperature fusing agent in the resin 811, and infiltrate the fiber matrix 810 with the resin 811 in which the silicon-containing filler and the high-temperature fusing agent are dispersed.

[0154] In some embodiments, the filler 842 further includes a lubricant, that is, the heat-resistant protective material 8 further includes a lubricant for more suitably molding the composition. The lubricant includes one or a combination of polyamide wax, polyethylene wax, and paraffin wax, and can increase the lubricity of the fiber matrix 810 and the resin 811 of the filler 842, and is used for more suitably molding the composition. For example, the heat-resistant protective material 8 includes a silicon-containing filler and a lubricant, and the usage amount of the lubricant is 10-40 wt% of the silicon-containing filler, such as 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt% or 40 wt%.

[0155] Optionally, in some embodiments, the filler 842 is a heat-reflective filler, that is, the heat-resistant protective material 8 further includes a heat-reflective filler, and the usage amount of the heat-reflective filler is 0-5 wt% of the heat-resistant protective material 8. In some other embodiments, for example, the filler 842 includes a silicon-containing filler and a heat-reflective filler, that is, the heat-resistant protective material 8 includes a silicon-containing filler and a heat-reflective filler, and the usage amount of the heat-reflective filler is 5-30 wt% of the silicon-containing filler. The heat-reflective filler may be applied to the surface of the composite layer or dispersed in the resin 811, and specifically, reference may be made to the form of adding a silicon-containing filler or a high-temperature fusing agent. The heat-reflective filler generally has the characteristic of a high melting point and can reduce the heat transfer. The heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium, and can be specifically selected according to needs.

[0156] Furthermore, in some embodiments, the heat-resistant protective material 8 further includes a colorant, and the colorant is used to adjust the appearance of the heat-resistant protective material 8 so as to ensure the appearance consistency of the heat-resistant protective material 8. The colorant includes one or more of carbon black, titanium white, iron black, oil-based color concentrate, and transition metal coloring ion oxides. The transition metal may be one or more of iron, chromium, copper, and nickel.

[0157] In some specific embodiments, the heat-resistant protective material 8 further includes a getter. As shown in FIG. 17, the getter is provided on the surface of the composite layer 81 to form a getter layer 82, or is embedded in the resin 811, and is used to absorb the combustible gas ejected from the pressure relief valve of the cell and delay the thermal runaway of the battery. The usage amount of the getter is 0 to 10 wt% of the heat-resistant protective material 8. The getter may be one or more of carbon molecular sieve, zeolite sieve, graphene, talc, and alumina.

[0158] Furthermore, the getter layer 82 is provided on the heat-receiving surface of the heat-resistant protective material 8 and is used to absorb the combustible gas ejected from the pressure relief valve of the cell and delay the thermal runaway of the battery. The getter layer 82 includes a case and the getter inside the case. For example, the case of the getter layer 82 is covered with a fiber resin composite layer.

[0159] Optionally, in some embodiments, referring to FIG. 18, the heat-resistant protective material 8 further includes a heat-insulating layer 83, and the heat-insulating layer 83 and the fiber resin composite layer 81 are provided in a laminated manner. In one specific embodiment, the heat-insulating layer 83 is provided on the non-heat-receiving surface of the heat-resistant protective material 8 and is used to block the transmission of the heat-receiving surface temperature of the heat-resistant protective material 8 to the non-heat-receiving surface temperature. The heat-insulating layer 83 includes an aerogel coating or an aerogel felt. The aerogel coating saves more space, and the aerogel felt can be surely provided in the composite layer.

[0160] Specifically, the aerogel coating is formed by drying the aerogel slurry after coating, and the aerogel slurry contains 10 to 50 parts of aerogel powder, 20 to 50 parts of adhesive, 1 to 5 parts of dispersant, 50 to 80 parts of solvent, and 1 to 5 parts of film-forming aid. The aerogel powder provides heat insulation performance for the aerogel coating. The adhesive provides the viscosity of the slurry and ensures that a film is formed after the final paint dries. The dispersant is used to disperse the aerogel powder to prevent the aggregation of the aerogel powder. The solvent is used to adjust the viscosity of the slurry and make it easier to disperse the aerogel powder. The film-forming aid helps the drying and film formation of the adhesive and is used to prevent the shedding of the aerogel powder in the aerogel coating.

[0161] Furthermore, the adhesive is one or more of silica sol, aluminum sol, sodium water glass, polyurethane, epoxy resin, acrylic emulsion, latex powder, modified starch, polyvinyl alcohol, and polyvinyl pyrrolidone. The dispersant is one or more of sodium pyrophosphate, sodium polyacrylate, sodium hexametaphosphate, stearamide, sorbeth tetraoleate, cellulose, and polyethylene glycol. The film-forming aid is one or more of benzyl alcohol, butoxyethanol, propylene glycol phenyl ether, and alcohol ester - 12.

[0162] Referring to FIG. 19, some embodiments of the present application provide a heat-resistant protective material 8, and the heat-resistant protective material 8 includes a functional layer 84. The functional layer 84 includes a first resin 841 and a filler 842 dispersed in the first resin 841. After the first resin 841 and the filler 842 are uniformly mixed to form a composition, the composition is cured to form the functional layer 84. That is, the functional layer 84 is a composite layer of resin and filler 842.

[0163] In some embodiments, the mass content of carbon element in the first resin 841 is greater than 40%, preferably, the mass content of carbon element in the first resin 841 is greater than 50%. When subjected to thermal shock, the first resin 841 can be carbonized to absorb heat, form a carbon layer, and resist heat penetration. The first resin 841 can include one or a combination of a phenolic resin, a benzoxazine resin, a furan resin, a polyurea, and a phenol-modified epoxy resin.

[0164] Optionally, in some embodiments, a first viscosity modifier is dispersed in the first resin 841. The viscosity modifier can reduce the viscosity of the high-viscosity resin, making it easier for the resin to infiltrate and penetrate into the fibers and facilitating the production and processing of products with a uniform thickness. Reducing the viscosity of the first resin 841 contributes to adding a filler 842, which is a functional material such as silicon-containing particles or chopped fibers. The usage amount of the first viscosity modifier is 1 to 10% of the volume of the first resin 841. When the usage amount of the first viscosity modifier is less than 1% of the volume of the first resin 841, the viscosity of the first resin 841 is high and the fluidity is low, making it difficult to form a product with a uniform thickness. When the usage amount of the first viscosity modifier is greater than 10% of the volume of the first resin 841, the viscosity is low and the fluidity is high, and during the processing and molding process of the composition, the solvent of the first resin 841 volatilizes to form bubble defects in the product. Further, the first viscosity modifier includes one or a combination of methanol, ethanol, ethyl acetate, acetone, and butanone and is used to reduce the viscosity of the first resin 841.

[0165] Optionally, in some embodiments, a first curing agent is dispersed in the first resin 841. The first curing agent can effectively shorten the curing time of the first resin 841 and contribute to the large-scale production and batch production of the heat-resistant protective material 8. In the case of a phenolic resin, hexamethylenetetramine is used as the first curing agent, and the amount of hexamethylenetetramine used is 2.5 to 3% of the mass of the phenolic resin. In the case of a furfural acetone resin, a phosphoric acid curing agent is used as the first curing agent, and the amount of the phosphoric acid curing agent used is 6 to 7% of the mass of the furfural acetone resin. Note that no curing agent is used for benzoxazine resin, furan resin, and polyurea.

[0166] Optionally, in some embodiments, a first flame retardant is dispersed in the first resin 841, and the amount of the first flame retardant used is 5 to 40% of the mass of the first resin 841. As the flame retardant, one or more of ammonium polyphosphate, aluminum hydroxide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) are used.

[0167] In some embodiments, the filler 842 is chopped fiber, and the volume ratio of the chopped fiber in the functional layer 84 is 50 to 80%. The chopped fiber includes one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, boron carbon fiber, and carbon nanotube.

[0168] In some other embodiments, the filler 842 is a first heat-reflective filler, and the volume ratio of the first heat-reflective filler in the functional layer 84 is 45 to 75%. The first heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium.

[0169] Optionally, in some other embodiments, the filler 842 includes a first silicon-containing filler, and the weight ratio of the first resin 841 to the first silicon-containing filler is 1:3 to 1:1. Generally, the silicon-containing filler begins to melt at a high temperature of 1200 °C. After the silicon-containing filler melts at a high temperature, the integrity of the heat-resistant protective material 8 can be increased, and the fire-resistant impact strength can be enhanced. A large amount of heat can be absorbed by the melting and vaporization of the silicon-containing filler, and the silicon-containing filler reacts with the carbon layer formed by the resin to generate solid silicon carbide. The solid silicon carbide can resist high-temperature erosion, high-temperature shear, and tension or compression, effectively enhancing the mechanical properties of the heat-resistant protective material 8 and avoiding the breakthrough of the heat-resistant protective material 8.

[0170] In one specific embodiment, the filler 842 includes chopped fibers and a first silicon-containing filler. The chopped fibers include one or more of carbon fibers, silicon carbide fibers, silicon nitride fibers, quartz fibers, aluminum silicate fibers, asbestos fibers, high-silica fibers, boron carbon fibers, and carbon nanotubes. The usage amount of the chopped fibers is 0 to 15 wt% of the first silicon-containing filler. The chopped fibers have a length of 0.05 to 30 mm and a diameter of 1 to 15 μm.

[0171] Optionally, in some embodiments, the first silicon-containing filler includes one or a combination of one or more of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, and talc. In one specific embodiment, the main components of the ceramic fine powder are silicon oxide and alumina. Alumina enhances the temperature resistance of the ceramic fine powder, and under the high-temperature action of thermal shock, silica reacts with the carbon layer formed by the carbonized resin to form silicon carbide.

[0172] Optionally, in some other embodiments, the first silicon-containing filler includes silica aerogel powder and mica powder, and the mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:1. Under the action of thermal shock, the temperature of the heat-receiving surface of the heat-resistant protective material 8 rises rapidly to form a steep temperature gradient. Silica aerogel is a porous material with mesopores and has an extremely low thermal conductivity. Silica aerogel can delay the heat transfer from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8. Silica aerogel is prone to shrinkage of the pore structure under the action of high temperature of 800°C to 1000°C, and the heat transfer delay effect from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8 becomes weak. If mica and silica aerogel are used in combination, mica has excellent heat resistance and heat insulation properties. Mica becomes brittle at 800°C to 1000°C, but its structure is not destroyed and it can still maintain its heat insulation performance. At 1050°C to 1100°C, the mica structure is destroyed. After the temperature of the heat-receiving surface of the heat-resistant protective material 8 rises to 1200°C, the silicon in the first silicon-containing filler reacts with the resin carbon layer to form porous solid silicon carbide to resist thermal shock, reduce the heat transfer from the heat-receiving surface to the non-heat-receiving surface, and this process absorbs heat to remove a large amount of heat and can further resist thermal shock.

[0173] Optionally, in some other embodiments, the first silicon-containing filler includes silica and aluminum oxide. The amount of silica used is 50 to 80 wt% of the first silicon-containing filler, and the amount of aluminum oxide used is 10 to 30 wt% of the first silicon-containing filler.

[0174] Optionally, in some embodiments, filler 842 includes a first silicon-containing filler and a first high-temperature fusing agent, and the usage amount of the first high-temperature fusing agent is 10 wt% to 40 wt% of the first silicon-containing filler. The material of the first high-temperature fusing agent is different from that of the first silicon-containing filler. The first high-temperature fusing agent has a low melting point and helps the first silicon-containing filler to melt or vaporize to form a carbon layer formed by the resin carbonization and solid silicon carbide. The first high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, and aluminum silicon powder.

[0175] Optionally, in some embodiments, filler 842 includes a first silicon-containing filler and a first lubricant, and the first lubricant helps in the molding of the composition. The usage amount of the first lubricant is 10 to 40 wt% of the first silicon-containing filler. The first lubricant includes one or more combinations of polyamide wax, polyethylene wax, paraffin wax, and talc. Polyamide wax, polyethylene wax, and paraffin wax can increase the lubricity of filler 842 in the resin and help in the molding of the composition, but they reduce the softening point of the composition and further reduce the heat resistance performance of the heat-resistant protective material 8. Therefore, the content of the first lubricant should not be too high.

[0176] Optionally, in some embodiments, filler 842 includes a first silicon-containing filler and a first heat-reflective filler. The first heat-reflective filler has the characteristic of a high melting point and can reduce the heat transfer. The usage amount of the first heat-reflective filler is 0 to 5 wt% of the first silicon-containing filler. The first heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium.

[0177] Optionally, in some embodiments, the functional layer 84 further includes a first ceramic precursor. The first ceramic precursor includes one or more of a polysilazane resin, a polyborosilazane resin, and a polycarbosilane resin. Under the action of thermal shock, the polysilazane resin and the polyborosilazane resin can generate ceramic materials such as SiCN and SiCNO, and can increase the temperature resistance and the flame-resistant shock strength of the heat-resistant protective material 8. The first ceramic precursor may be cured after being mixed with the first resin 841 and the filler 842 to form a functional layer, or may be applied to the surface of the composite layer of the first resin 841 and the filler 842. While the ceramic precursor reduces the bending strength of the heat-resistant protective material at room temperature, the ceramic precursor reacts at high temperatures to generate a ceramic material and does not reduce the temperature resistance and the flame-resistant shock strength of the heat-resistant protective material 8. In one embodiment, the volume ratio of the first ceramic precursor to the sum of the volumes of the first ceramic precursor and the first resin 841 is less than 50%, or the mass ratio of the first ceramic precursor to the sum of the masses of the first ceramic precursor and the first resin 841 is less than 50%, thereby ensuring that the heat-resistant protective material has excellent bending strength at room temperature, controlling the cost of the heat-resistant protective material 8, increasing the temperature resistance and the flame-resistant shock strength of the heat-resistant protective material 8, and maintaining the market competitiveness advantage of the heat-resistant protective material 8.

[0178] Furthermore, in some embodiments, referring to FIGS. 20 and 21, the heat-resistant protective material 8 further includes a reinforcing layer 85 provided by laminating with the functional layer 84. The first resin 841 of the functional layer 84 penetrates into the reinforcing layer 85 under the action of hot pressing, adheres to the reinforcing layer 85 and cures and composites. The reinforcing layer 85 is used to reinforce the room-temperature mechanical properties of the functional layer 84.

[0179] In some embodiments, referring to FIG. 20, the reinforcing layer 85 is a fiber matrix 810, that is, the pure fiber matrix 810 is adopted as the reinforcing layer 85. Further, the fiber matrix 810 and the functional layer 84 can be laminated. The first resin 841 in the functional layer 84 partially penetrates into the fiber matrix 810 by hot pressing. Since the penetration depth of the first resin 841 by the hot pressing method is limited, the thickness of the pure fiber matrix 810 should not be too large. In one embodiment, the thickness range of the pure fiber matrix 810 is <0.2 mm, and in the hot pressing process, the first resin 841 in the functional layer 84 can infiltrate the entire pure fiber matrix 810.

[0180] The fiber matrix 810 includes a fiber cloth and / or a fiber felt, and the fibers of the fiber matrix 810 include one or more of carbon fibers, silicon carbide fibers, silicon nitride fibers, quartz fibers, aluminum silicate fibers, asbestos fibers, high silica fibers, boron carbon fibers, and carbon nanotubes. The fiber cloth and / or the fiber felt are used to reinforce the room temperature mechanical properties of the functional layer 84. The fiber cloth is one or more of a fiber twill fabric, a fiber satin fabric, a fiber uniaxial fabric, and a fiber multi-axial fabric. In the fiber twill fabric, the warp and weft intersect at least once every two or more, and by adding the intersection points of the warp and weft, the tissue structure of the fabric is changed. The warp or weft of the fiber satin fabric forms several separate warp or weft tissue points that are not connected to each other in the fabric. The fabric surface appears to be almost entirely covered by the warp or weft and seems to have diagonal lines on the surface, but it does not have obvious diagonal lines like a twill fabric. It has characteristics such as fewer intersections between the warp and weft, a smooth and bright appearance, and a soft texture. The fiber uniaxial fabric has yarns inserted in the horizontal or vertical direction of the fabric, has high fiber continuity and linearity, is a typical anisotropic material, and has good curling properties along the direction perpendicular to the yarn. The fiber multi-axial fabric includes warp yarns, core yarns, and braided yarns. The warp and weft do not intersect, can form two parallel yarn layers and be arranged perpendicular to each other, and are further connected by the braided yarns. Since there are no fibers or only chopped fibers in the functional layer 84, the heat-resistant protective material 8 made of a large-sized functional layer 84 may crack or break when transported at room temperature and in a thermal shock environment. The reinforcement layer 85 strengthens the mechanical properties of the functional layer 84 and improves the room temperature mechanical properties and thermal shock resistance of the heat-resistant protective material 8. Also, when using the heat-resistant protective material 8, the reinforcement layer 85 is used as the heat-receiving surface. Due to the action of thermal shock, heat is absorbed by the ablation of the reinforcement layer 85, providing resistance to thermal shock for the functional layer 84.

[0181] When there is only the functional layer 84, that is, the composite layer of the first resin 841 and the filler 842, it is understood that the formed heat-resistant protective material 8 has low impact resistance performance and can be used for small battery cells. The heat-resistant protective material 8 formed after laminating the functional layer 84 and the reinforcing layer 85 has high heat shock resistance performance and can be used for large battery cells. Specifically, it can be selected according to actual needs.

[0182] Optionally, in some other embodiments, referring to FIG. 21, the reinforcing layer 85 includes a fiber matrix 810 and a second resin 850. The second resin 850 is dispersed in the voids of the fiber matrix 810 and / or on the surface of the fiber matrix 810 to form a composite layer. The volume ratio of the fiber matrix 810 in the reinforcing layer 85 is 50% - 75%. That is, the fiber resin composite layer 81 provided by the above embodiment is adopted for the reinforcing layer 85. Further, the number of layers of the fiber cloth and / or fiber felt in the fiber matrix 810 may be one layer, two layers or multiple layers. After laminating two or more layers of fiber cloth and / or fiber felt, they are adhered and cured by the second resin 850. The second resin 850 includes one or a combination of multiple of phenolic resin, benzoxazine resin, furan resin, polyurea, and phenol-modified epoxy resin. The mass content of carbon element in the second resin 850 is greater than 40%. By the composite of the reinforcing layer 85 containing the second resin 850 and the functional layer 84 containing the first resin 841, the resins in the reinforcing layer 85 and the functional layer 84 are distributed more uniformly and sufficiently. The reinforcing layer 85 impregnated with the second resin 850 can be used as the heat-receiving surface. The second resin 850 absorbs heat and carbonizes, resists heat penetration, and plays a role in protecting the functional layer 84.

[0183] Furthermore, the thickness ratio of the functional layer 84 to the strengthening layer 85 is (8 - 10):(1 - 4). The strengthening layer 85 is ablated as the heat-receiving surface and can protect the functional layer 84. The functional layer 84 provides the main impact resistance performance to the heat-resistant protective material 8. Furthermore, the heat-resistant protective material 8 includes two layers of strengthening layers 85, namely the first strengthening layer and the second strengthening layer, which are respectively provided on both opposite sides of the functional layer 84 to form a sandwich-like structure. The thickness ratio of the first strengthening layer, the functional layer 84, and the second strengthening layer is (1 - 2):(8 - 10):(1 - 2), which enhances the symmetry of the mechanical properties on both opposite sides of the heat-resistant protective material 8. Under the action of thermal shock, carbonization ablation occurs on the first strengthening layer of the heat-receiving surface of the heat-resistant protective material 8 to absorb heat, and the second strengthening layer on the non-heat-receiving surface can maintain the structural integrity of the functional layer 84.

[0184] Optionally, in some embodiments, a second viscosity modifier is dispersed in the second resin 850, and the usage amount of the second viscosity modifier is 1 - 10% of the volume of the second resin 850. Optionally, in some embodiments, a second curing agent is dispersed in the second resin 850. Optionally, in some embodiments, a second flame retardant is dispersed in the second resin 850, and the usage amount of the second flame retardant is 5 - 40% of the mass of the second resin 850. The second viscosity modifier, the second curing agent, and the second flame retardant are respectively similar to the materials and / or components of the first viscosity modifier, the first curing agent, and the first flame retardant in the above embodiments. Specifically, reference can be made to the above embodiments, and details are not described here.

[0185] Optionally, in some embodiments, a phase change material is further dispersed in the second resin 850, and the usage amount of the phase change material is 5% - 20% of the volume of the fiber matrix 810. The phase change material can absorb heat to provide resistance to thermal shock and can reduce heat transfer from the heat-receiving surface to the non-heat-receiving surface. In order to avoid the phase change material decomposing under the action of thermal shock to generate air bubbles between the functional layer 84 and the strengthening layer 85 and within the functional layer 84, which significantly accelerates the ablation of the functional layer 84 and affects the thermal shock resistance performance of the heat-resistant protective material 8, the phase change material is added and used only within the strengthening layer 85. Furthermore, the phase change material employs a hydrated salt component.

[0186] Optionally, in some embodiments, the reinforcing layer 85 further includes a second ceramic precursor. The second ceramic precursor includes one or more of a polysilazane resin 811, a polyborosilazane resin 811, and a polycarbosilane resin 811. Under the action of thermal shock, ceramic materials such as SiCN and SiCNO can be generated, and the temperature resistance and flame-resistant shock strength of the heat-resistant protective material 8 can be increased. In some embodiments, the mixture of the second resin 850 and the second ceramic precursor is dispersed in the voids of the fiber matrix 810 and / or covers two opposite surfaces of the fiber matrix 810. Optionally, in some other embodiments, the second ceramic precursor is applied to one surface of the fiber resin composite layer or is applied to two opposite surfaces of the fiber resin composite layer. While the bending strength of the heat-resistant protective material at room temperature is reduced by the ceramic precursor, the ceramic precursor reacts at high temperatures to generate a ceramic material and does not reduce the temperature resistance and flame-resistant shock strength of the heat-resistant protective material 8. In one embodiment, the ratio of the volume of the second ceramic precursor to the sum of the volumes of the second ceramic precursor and the second resin 850 is less than 50%, or the ratio of the mass of the second ceramic precursor to the sum of the masses of the second ceramic precursor and the second resin 850 is less than 50%, thereby ensuring that the heat-resistant protective material has excellent bending strength at room temperature, while controlling the cost of the heat-resistant protective material 8, increasing the temperature resistance and flame-resistant shock strength of the heat-resistant protective material 8, and maintaining the market competitiveness advantage of the heat-resistant protective material 8.

[0187] Optionally, in some embodiments, the fiber matrix 810 includes a first fiber matrix and a second fiber matrix, the second resin 850 is dispersed within the voids of the first fiber matrix and / or covers two opposing surfaces of the first fiber matrix to form a first composite layer, the second ceramic precursor is dispersed within the voids of the second fiber matrix and / or covers two opposing surfaces of the second fiber matrix to form a second composite layer. In one specific embodiment, the first composite layer and the second composite layer are provided in a stacked manner to form a stacked structure. In another specific embodiment, two first composite layers sandwich at least one second composite layer to form a stacked structure. Optionally, in another specific embodiment, two second composite layers sandwich at least one first composite layer to form a stacked structure. In another specific embodiment, a plurality of first composite layers and a plurality of second composite layers are provided alternately in a stacked manner.

[0188] Optionally, in some embodiments, referring to FIG. 22, the reinforcing layer 85 includes a fiber matrix 810, a second resin 850, and a filler 842, and the filler 842 includes one or more of a second silicon-containing filler, a second high-temperature fusing agent, a second lubricant, and a second heat-reflective filler.

[0189] In some embodiments, the filler 842 is a second silicon-containing filler, and the second silicon-containing filler occupies 40% to 70% of the volume of the fiber matrix 810. The second silicon-containing filler may be coated on the surface of the fiber resin composite layer 81 or embedded in the second resin 850. The second silicon-containing filler includes one or a combination of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, and talc. In one specific embodiment, the second silicon-containing filler includes silica aerogel powder and mica powder, and the mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:1. In another embodiment, the second silicon-containing filler includes silica and aluminum oxide, the amount of silica used is 50% to 80 wt% of the second silicon-containing filler, and the amount of aluminum oxide used is 10% to 30 wt% of the second silicon-containing filler. The second silicon-containing filler is coated on the surface of the composite layer or embedded in the second resin 850.

[0190] Optionally, in some embodiments, the filler 842 includes a second silicon-containing filler and a second high-temperature fusing agent, that is, the reinforcing layer 85 includes a second silicon-containing filler and a second high-temperature fusing agent, and the amount of the second high-temperature fusing agent used is 10 wt% to 40 wt% of the second silicon-containing filler. The second high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, and aluminum silicon powder, and the material of the second high-temperature fusing agent is different from the material of the second silicon-containing filler.

[0191] Optionally, in some embodiments, the reinforcing layer 85 includes a second silicon-containing filler and a second lubricant, and the amount of the second lubricant used is 10 to 40 wt% of the second silicon-containing filler. The second lubricant includes one or a combination of polyamide wax, polyethylene wax, and paraffin wax.

[0192] Optionally, in some embodiments, the filler 842 includes a second silicon-containing filler and a second heat-reflective filler, that is, the reinforcing layer 85 includes a second silicon-containing filler and a second heat-reflective filler, and the usage amount of the second heat-reflective filler is 5 to 30 wt% of the second silicon-containing filler. The second heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium.

[0193] Optionally, in some embodiments, the reinforcing layer 85 includes a fiber matrix 810, a second resin 850, and a colorant. The colorant includes one or more of carbon black, titanium white, iron black, oil-based color concentrate, and transition metal coloring ion oxides.

[0194] Optionally, in some embodiments, the heat-resistant protective material 8 further includes a getter. The getter is filled in the functional layer 84 and / or the reinforcing layer 85, or the getter is provided between the functional layer 84 and the reinforcing layer 85 to form a getter layer 82. The getter is filled in the functional layer 84 and / or the reinforcing layer 85 of the heat-resistant protective material 8 as the filler 842, absorbs the combustible gas ejected from the pressure relief valve of the cell, and is used to delay the thermal runaway of the battery. The getter is one or more of carbon molecular sieve, zeolite sieve, graphene, talc, and alumina. In some embodiments, referring to FIG. 23, the getter layer 82 is provided on the side of the reinforcing layer 85 away from the functional layer 84, and the getter layer 82 includes a case and the getter inside the case.

[0195] Optionally, in some embodiments, referring to FIG. 24, the heat-resistant protective material 8 further includes a heat-insulating layer 83, and the heat-insulating layer 83 is provided on the side away from the reinforcing layer 85 of the functional layer 84 and is used to block the transmission of the heat-receiving surface temperature of the heat-resistant protective material 8 to the non-heat-receiving surface temperature. The heat-insulating layer 83 includes an aerogel coating or an aerogel felt. The aerogel coating saves more space, and the aerogel felt can be more firmly provided in a composite layer. Specifically, the aerogel coating is formed by drying after coating an aerogel slurry. For details, refer to the above aerogel coating.

[0196] Referring to FIGS. 25 and 26, some embodiments of the present application provide a heat-resistant protective material 8, and the heat-resistant protective material 8 includes a reinforcing layer 85, a functional layer 84, and a reinforcing layer 86 provided in sequence from the heat-receiving surface to the non-heat-receiving surface. The functional layer 84 includes a first resin 841 and a filler 842 dispersed in the first resin 841. Both the reinforcing layer 85 and the reinforcing layer 86 include a fiber matrix 810.

[0197] The functional layer 84 is provided between the reinforcement layer 85 and the reinforcing layer 86. In some embodiments, referring to FIG. 25, both the reinforcement layer 85 and the reinforcing layer 86 only include the fiber matrix 810, that is, both the reinforcement layer 85 and the reinforcing layer 86 are pure fiber matrices 810. The first resin 841 penetrates into the reinforcement layer 85 and the reinforcing layer 86 under the action of hot pressing, so that the functional layer 84, the reinforcement layer 85 and the reinforcing layer 86 are adhered, cured and combined. In some other embodiments, referring to FIG. 26, the reinforcement layer 85 and / or the reinforcing layer 86 include the fiber matrix 810 and the second resin 850, that is, the reinforcement layer 85 and / or the reinforcing layer 86 adopt the fiber resin composite layer provided by the above embodiment, and the functional layer 84 adopts the resin filler composite layer provided by the above embodiment. The first resin 841 in the functional layer 84 and the second resin 850 in the reinforcement layer 85 and / or the reinforcing layer 86 can be fused with each other, adhered, cured and combined under the action of hot pressing. The structures of the reinforcement layer 85 and the reinforcing layer 86 are the same, but the melting point of the fiber matrix 810 of the reinforcing layer 86 may be higher than the melting point of the fiber matrix 810 of the reinforcement layer 85, or may be the same as the melting point of the fiber matrix 810 of the reinforcement layer 85. The materials of the fiber matrix 810 of the reinforcing layer 86 and the fiber matrix 810 of the reinforcement layer 85 may be the same or different.

[0198] The fiber matrix 810 with a high melting point is generally understood to be more costly than the fiber matrix 810 with a low melting point. To control the cost, in one embodiment of the present application, the fiber matrix 810 with a high melting point is adopted only on the non-heated surface, and the fiber matrix 810 with a low melting point is adopted on the heated surface. In another embodiment of the present application, the fiber matrix 810 with a high melting point may be adopted on either the heated surface or the non-heated surface of the functional layer 84, or the fiber matrix 810 with a low melting point may be adopted. In the present application, the fiber material of the fiber matrix 810 with a low melting point includes one or more of high silica fiber, quartz fiber, glass fiber, and basalt fiber, and the fiber material of the fiber matrix 810 with a high melting point includes one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, and boron carbon fiber.

[0199] The first resin 841 is used to form a carbon layer that chars and absorbs heat when subjected to a thermal shock and resists heat penetration. The mass content of carbon element in the first resin 841 is greater than 40%, for example, 42%, 45%, 50%, 55%, 60%, 65% or 70%, etc., and can include one or a combination of more of phenol resin 811, benzoxazine resin 811, furan resin 811, polyurea, and phenol-modified epoxy resin 811, and specifically can be selected according to needs.

[0200] Furthermore, in some embodiments, a first viscosity modifier is dispersed in the first resin 841. The first viscosity modifier is used to reduce the viscosity of the high-viscosity first resin 841, making it easier for the first resin 841 to infiltrate and penetrate into the fiber matrix 810 and facilitating the production and processing of products with a uniform thickness. In the embodiments of the present application, the usage amount of the first viscosity modifier is 1% to 10% of the volume of the first resin 841. For example, it can be 1%, 5%, 7%, or 10%, etc. When the usage amount of the first viscosity modifier is less than 1% of the volume of the first resin 841, the viscosity of the first resin 841 is high, the fluidity is low, and it is difficult to form a product with a uniform thickness. When the usage amount of the first viscosity modifier is greater than 10% of the volume of the first resin 841, the first resin 841 has a low viscosity and high fluidity, and during the processing and molding process of the composition, the solvent of the first resin 841 volatilizes, resulting in the formation of bubble defects in the product. In one specific embodiment, the first viscosity modifier includes one or a combination of methanol, ethanol, ethyl acetate, acetone, and butanone.

[0201] Furthermore, in some embodiments, a first curing agent is dispersed in the first resin 841. The first curing agent can effectively shorten the curing time of the first resin 841, contributing to the large-scale production and batch production of the heat-resistant protective material 8. When the first resin 841 is a phenolic resin, hexamethylenetetramine is used as the first curing agent, and the usage amount of hexamethylenetetramine is 2.5% to 3% of the mass of the phenolic resin. When the first resin 841 is a furfural acetone resin, a phosphoric acid curing agent is used as the first curing agent, and the usage amount of the phosphoric acid curing agent is 6% to 7% of the mass of the furfural acetone resin. Also, when the first resin 841 is a benzoxazine resin, a furan resin, or a polyurea, no curing agent is used.

[0202] Furthermore, in some embodiments, a first flame retardant is dispersed in the first resin 841, and the amount of the first flame retardant used is 5% to 40% of the mass of the first resin 841, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%. As the first flame retardant, one or more of ammonium polyphosphate, aluminum hydroxide, and DOPO are used. Ammonium polyphosphate is dehydrated by heating under high-temperature conditions to generate polyphosphoric acid or metaphosphoric acid, and can act as a strong dehydrating agent with the carbon-forming substances in the flame retardant system to form a single-layer carbon layer. The non-combustible gas generated from the gas source acts to form an expanded carbon layer to isolate the air and play a role in blocking the fire source, achieving the purpose of flame retardancy. When aluminum hydroxide is heated, it strongly undergoes an endothermic reaction, absorbing a large amount of heat and playing a role in cooling the polymer. At the same time, it decomposes and releases crystal water, and the water vapor generated by the endothermic absorption of the crystal water can dilute the combustible gas, further suppressing the spread of combustion. When the DOPO flame retardant is heated, a strong endothermic reaction occurs, preventing the spread of combustion, and further increasing the heat capacity of the polymer.

[0203] Furthermore, in some embodiments, the filler 842 is a first chopped fiber, and the first chopped fiber is dispersed in the first resin 841, which can increase the strength uniformity of the functional layer 84. The volume ratio of the first chopped fiber in the functional layer 84 is 50% to 80%, for example, 50%, 55%, 60%, 65%, 70%, 75% or 80%. The first chopped fiber includes one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high-silica fiber, boron carbon fiber, and carbon nanotube.

[0204] In some other embodiments, the filler 842 is a first heat-reflective filler, and the volume ratio of the first heat-reflective filler in the functional layer 84 is 45% to 75%, such as 45%, 50%, 55%, 60%, 65%, 70% or 75%. The first heat-reflective filler includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium. The first heat-reflective filler generally has a high melting point and can reduce heat transfer.

[0205] In some other embodiments, the filler 842 includes a first silicon-containing filler, and the weight ratio of the first resin 841 to the first silicon-containing filler is 1:3 to 1:1, such as 1:3, 1:2, 2:3 or 1:1. Usually, the first silicon-containing filler begins to melt at a high temperature of 1200 °C, can absorb a large amount of heat by vaporization of the first silicon-containing filler, and the first silicon-containing filler reacts with the carbon layer formed by the first resin 841 to generate solid silicon carbide. The solid silicon carbide can resist high-temperature erosion, high-temperature shear, and tension or compression, effectively enhancing the mechanical properties of the heat-resistant protective material 8 and avoiding breakthrough of the heat-resistant protective material 8.

[0206] The first silicon-containing filler includes one or more combinations of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, and talc. The main components of the ceramic fine powder are silicon oxide and alumina. Alumina can enhance the temperature resistance of the ceramic fine powder. Under the high-temperature action of thermal shock, silica reacts with the carbon layer formed by the resin carbonization to form silicon carbide.

[0207] In some specific embodiments, the first silicon-containing filler includes silica aerogel powder and mica powder, and the mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:1. When subjected to thermal shock, the temperature of the heat-receiving surface of the heat-resistant protective material 8 rises rapidly to form a steep temperature gradient. Silica aerogel is a porous material with mesopores and has an extremely low thermal conductivity. Silica aerogel can delay the heat transfer from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8. Also, silica aerogel is prone to pore structure contraction under the action of high temperatures of 800°C to 1000°C, and the heat transfer delay effect from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8 becomes weak. Mica has excellent heat resistance and heat insulation properties, and mica can maintain its heat insulation performance at 800°C to 1000°C. After the temperature of the heat-receiving surface of the heat-resistant protective material 8 rises to 1200°C, the silicon in the first silicon-containing filler reacts with the carbon layer of the first resin 841 to form porous solid silicon carbide, which resists thermal shock, reduces heat transfer from the heat-receiving surface to the non-heat-receiving surface, and this process absorbs heat to remove a large amount of heat and can further resist thermal shock.

[0208] In another specific embodiment, the first silicon-containing filler includes silica and aluminum oxide. The amount of silica used is 50 to 80 wt% of the first silicon-containing filler, such as 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt% or 80 wt%, etc. The amount of aluminum oxide used is 10 to 30 wt% of the first silicon-containing filler, such as 10 wt%, 15 wt%, 20 wt%, 25 wt% or 30 wt%, etc. When subjected to high-temperature thermal shock, silica reacts with the carbon layer formed by the carbonization of the first resin 841 to form silicon carbide, and aluminum oxide can enhance the temperature resistance.

[0209] Furthermore, in some embodiments, the filler 842 includes a first silicon-containing filler and a first high-temperature fusing agent, and the usage amount of the first high-temperature fusing agent is 10 wt% to 40 wt% of the first silicon-containing filler. The first high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, and aluminum silicon powder. It should be noted that the material of the first high-temperature fusing agent is different from that of the first silicon-containing filler. The first high-temperature fusing agent helps to form a carbon layer formed by the melting or vaporization of the first silicon-containing filler and the carbonization of the first resin 841 and solid silicon carbide.

[0210] Furthermore, in some embodiments, the filler 842 includes a first silicon-containing filler and a first lubricant, and is used to increase the lubricity of the fiber matrix 810 and the first resin 841 of the first silicon-containing filler, which is helpful for the molding of the composition. The first lubricant includes one or more combinations of polyamide wax, polyethylene wax, paraffin wax, and talc. The usage amount of the first lubricant is 10 to 40 wt% of the first silicon-containing filler, such as 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or 40 wt%. When the usage amount of the first lubricant is less than 10 wt% of the first silicon-containing filler, the effect of the first lubricant is limited. When the usage amount of the first lubricant is greater than 40 wt% of the first silicon-containing filler, it reduces the softening point of the composition and further reduces the heat resistance performance of the heat-resistant protective material 8.

[0211] Furthermore, in some embodiments, the functional layer 84 further includes a first ceramic precursor, the first ceramic precursor includes one or more of polysilazane resin 811, polyborosilazane resin 811, and polycarbosilane resin 811, and when subjected to thermal shock, it can generate ceramic materials such as SiCN and SiCNO, and is used to increase the temperature resistance and flame shock resistance of the heat-resistant protective material 8. The first ceramic precursor may be cured after being mixed with the first resin 841 and the filler 842 to form a functional layer, or may be coated on the surface of the composite layer of the first resin 841 and the filler 842. In one embodiment, the volume ratio of the first ceramic precursor to the sum of the volumes of the first ceramic precursor and the first resin 841 is less than 50%, or the mass ratio of the first ceramic precursor to the sum of the masses of the first ceramic precursor and the first resin 841 is less than 50%, thereby ensuring that the heat-resistant protective material has excellent bending strength at room temperature, controlling the cost of the heat-resistant protective material 8, increasing the temperature resistance and flame shock resistance of the heat-resistant protective material 8, and maintaining the market competitiveness advantage of the heat-resistant protective material 8.

[0212] Optionally, in some embodiments, the filler 842 includes a first silicon-containing filler and a first chopped fiber. The first chopped fiber is provided in the functional layer 84 and can increase the strength uniformity of the functional layer 84. The first chopped fiber includes one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high-silica fiber, boron carbon fiber, and carbon nanotube. The usage amount of the first chopped fiber is 0 to 15 wt% of the first silicon-containing filler. The first chopped fiber has a length of 0.05 to 30 mm and a diameter of 1 to 15 μm.

[0213] Optionally, in some embodiments, the filler 842 includes a first silicon-containing filler and a first heat-reflective filler. The first heat-reflective filler has the characteristic of a high melting point and can reduce the heat transfer. It includes one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium. The usage amount of the first heat-reflective filler is 0 to 5 wt% of the first silicon-containing filler.

[0214] The strengthening layer 85 is used as a heat-receiving surface. The strengthening layer 85 enhances the mechanical properties of the functional layer 84, improves the room-temperature mechanical properties and heat shock resistance of the heat-resistant protective material 8. Under the action of heat shock, the strengthening layer 85 ablates and absorbs heat, providing the functional layer 84 with resistance to heat shock. The fiber matrix 810 of the strengthening layer 85 includes one or more of high-silica fiber, quartz fiber, glass fiber, and basalt fiber. The fiber matrix 810 includes fiber cloth and / or fiber felt. The fiber cloth is one or more of fiber twill fabric, fiber satin fabric, fiber uniaxial fabric, and fiber multi-axial fabric. The fiber matrix 810 includes fiber cloth and / or fiber felt provided in a stacked manner.

[0215] Optionally, in some embodiments, the strengthening layer 85 includes a second resin 850. The fiber matrix 810 and the second resin 850 together form a composite layer. The second resin 850 is dispersed in the voids within and / or on the surface of the fiber matrix 810. The volume ratio of the fiber matrix 810 of the strengthening layer 85 to the strengthening layer 85 is 50% to 75%. The mass content of carbon element in the second resin 850 is greater than 40%. By the composite of the strengthening layer 85 containing the second resin 850 and the functional layer 84, the problem that the impregnation of the resin 811 in the functional layer 84 into the strengthening layer 85 is not uniform and sufficient after the composite of the strengthening layer 85 without the resin 811 and the functional layer 84 can be avoided. Using the strengthening layer 85 impregnated with the second resin 850 as the heat-receiving surface, the second resin 850 absorbs heat and carbonizes, providing the function of resisting heat penetration and protecting the functional layer 84. Furthermore, the strengthening layer 85 includes a single layer or two or more layers of fiber cloth. The two or more layers of fiber cloth are adhered and cured by the second resin 850 after being stacked.

[0216] The second resin 850 of the reinforcing layer 85 includes one or a combination of a phenol resin, a benzoxazine resin, a furan resin, a polyurea, and a phenol-modified epoxy resin. A second viscosity modifier is dispersed in the second resin 850. The second viscosity modifier is used to reduce the viscosity of the high-viscosity first resin 841, so that the first resin 841 can easily infiltrate and penetrate into the fiber matrix 810 and is easy to produce and process into a product with a uniform thickness. In the embodiments of the present application, the usage amount of the second viscosity modifier is 1 to 10% of the volume of the second resin 850. For example, it is 1%, 5%, 7%, or 10%, etc. When the usage amount of the second viscosity modifier is less than 1% of the volume of the second resin 850, the viscosity of the second resin 850 is high, the fluidity is low, and it is difficult to form a product with a uniform thickness. When the usage amount of the second viscosity modifier is greater than 10% of the volume of the second resin 850, the second resin 850 has a low viscosity and high fluidity, and during the processing and molding process of the composition, the solvent of the second resin 850 volatilizes and air bubble defects are formed in the product. In one specific embodiment, the second viscosity modifier includes one or a combination of methanol, ethanol, ethyl acetate, acetone, and butanone.

[0217] A second curing agent is dispersed in the second resin 850 of the reinforcing layer 85. The second curing agent can effectively shorten the curing time of the first resin 841 and contribute to the large-scale production and batch production of the heat-resistant protective material 8. When the second resin 850 is a phenol resin 811, hexamethylenetetramine is used as the second curing agent, and the usage amount of hexamethylenetetramine is 2.5 to 3% of the mass of the phenol resin. When the second resin 850 is a furfural acetone resin, a phosphoric acid curing agent is used as the second curing agent, and the usage amount of the phosphoric acid curing agent is 6 to 7% of the mass of the furfural acetone resin. Also, when the second resin 850 is a benzoxazine resin, a furan resin, or a polyurea, no curing agent is used.

[0218] The second flame retardant is dispersed in the second resin 850 of the reinforcing layer 85, and the usage amount of the second flame retardant is 5 to 40% of the mass of the second resin 850, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, etc. The usage amount of the second flame retardant is 5 to 40% of the mass of the second resin 850, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, etc. As the second flame retardant, one or more of ammonium polyphosphate, aluminum hydroxide, and DOPO are used.

[0219] The fiber resin composite layer of the reinforcing layer 85 further contains a second silicon-containing filler, and the second silicon-containing filler occupies 40 to 70% of the volume of the fiber matrix 810, for example, 40%, 45%, 50%, 55%, 60%, 65% or 70%, etc. Usually, the second silicon-containing filler begins to melt at a high temperature of 1200 °C, absorbs a large amount of heat due to the vaporization of the second silicon-containing filler, and the second silicon-containing filler reacts with the carbon layer formed by the second resin 850 to generate solid silicon carbide. The solid silicon carbide can resist high-temperature erosion, high-temperature shear, and tension or compression, effectively enhancing the mechanical properties of the heat-resistant protective material 8 and avoiding the breakthrough of the heat-resistant protective material 8.

[0220] The second silicon-containing filler of the reinforcing layer 85 includes one or a combination of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, talc, etc. The main components of the ceramic fine powder are silicon oxide and alumina. Alumina can enhance the temperature resistance of the ceramic fine powder. Under the high-temperature action of thermal shock, silica reacts with the carbon layer formed by the carbonization of the resin 811 to form silicon carbide.

[0221] In some specific embodiments, the second silicon-containing filler of the reinforcing layer 85 includes silica aerogel powder and mica powder, and the mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:1. When subjected to thermal shock, the temperature of the heat-receiving surface of the heat-resistant protective material 8 rises rapidly to form a steep temperature gradient. Silica aerogel is a porous material with mesopores and has an extremely low thermal conductivity. Silica aerogel can delay the heat transfer from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8. Also, silica aerogel is prone to pore structure shrinkage under the action of high temperatures of 800°C to 1000°C, and the heat transfer delay effect from the heat-receiving surface to the non-heat-receiving surface of the heat-resistant protective material 8 becomes weak. Mica has excellent heat resistance and heat insulation properties, and mica can maintain its heat insulation performance at 800°C to 1000°C. After the temperature of the heat-receiving surface of the heat-resistant protective material 8 rises to 1200°C, the silicon in the second silicon-containing filler reacts with the carbon layer of the first resin 841 to form porous solid silicon carbide, which resists thermal shock, reduces heat transfer from the heat-receiving surface to the non-heat-receiving surface, and this process absorbs heat to remove a large amount of heat and can further resist thermal shock.

[0222] In another specific embodiment, the second silicon-containing filler of the reinforcing layer 85 includes silica and aluminum oxide. The usage amount of silica is 50-80 wt% of the second silicon-containing filler, such as 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt% or 80 wt%, etc. The usage amount of aluminum oxide is 10-30 wt% of the second silicon-containing filler, such as 10 wt%, 15 wt%, 20 wt%, 25 wt% or 30 wt%, etc. When subjected to high-temperature thermal shock, silica reacts with the carbon layer formed by the carbonization of the second resin 850 to form silicon carbide, and aluminum oxide can enhance the temperature resistance. Usually, it begins to melt at a high temperature of 1200 °C in the second silicon-containing filler, and a large amount of heat can be absorbed by the vaporization of the second silicon-containing filler. The second silicon-containing filler reacts with the carbon layer formed by the second resin 850 to generate solid silicon carbide. The solid silicon carbide can resist high-temperature erosion, high-temperature shear, and tension or compression, effectively enhancing the mechanical properties of the heat-resistant protective material 8 and avoiding the breakthrough of the heat-resistant protective material 8.

[0223] Furthermore, in some embodiments, the fiber resin composite layer of the reinforcing layer 85 further includes a phase change material. The phase change material is dispersed in the second resin 850, and the usage amount of the phase change material is 5%-20% of the volume of the fiber matrix 810. It is used to absorb heat when subjected to thermal shock to provide resistance to thermal shock and can reduce the heat transfer from the heated surface to the non-heated surface. Due to the action of thermal shock, the phase change material thermally decomposes to generate bubbles between the functional layer 84 and the reinforcing layer 85 and within the functional layer 84, significantly accelerating the ablation of the functional layer 84. To avoid affecting the thermal shock resistance performance of the heat-resistant protective material 8, the phase change material is added and used only within the reinforcing layer 85.

[0224] Furthermore, in some embodiments, the fiber resin composite layer of the reinforcing layer 85 further includes a colorant. The colorant includes one or more of carbon black, titanium white, iron black, oil-based color concentrate, and transition metal coloring ion oxides, and is used to adjust the appearance of the heat-resistant protective material 8 and ensure the consistency of the appearance of the heat-resistant protective material 8.

[0225] In some embodiments, the heat resistance performance of the reinforcing layer 86 is better, which cooperates with the strengthening layer 85 to realize the structural symmetry of the upper and lower surfaces of the functional layer 84, enhance the high-temperature mechanical properties of the functional layer 84, and maintain the structural integrity of the heat-resistant protection material 8 as the non-heated surface after the thermal shock action. Further, in some embodiments of the present application, the ratio of the thicknesses of the strengthening layer 85, the functional layer 84, and the reinforcing layer 86 is (1-2):(8-10):(1-2). The reinforcing layer 86 includes a fiber matrix 810, and the structure of the fiber matrix 810 of the reinforcing layer 86 is similar to that of the fiber matrix 810 of the strengthening layer 85. Specifically, the above embodiments can be referred to and will not be described in detail here. However, the melting point of the fiber matrix 810 of the reinforcing layer 86 is higher than that of the fiber matrix 810 of the strengthening layer 85. The fiber matrix 810 of the reinforcing layer 86 includes one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high-silica fiber, and boron carbon fiber.

[0226] In some embodiments, the reinforcing layer 86 includes a second resin 850, and the fiber matrix 810 and the second resin 850 jointly form a composite layer. The second resin 850 is dispersed in the voids of the fiber matrix 810 and / or on the surface of the fiber matrix 810. The fiber matrix 810 of the reinforcing layer 86 accounts for 50%-75% of the volume ratio of the reinforcing layer 86, and the mass content of carbon element in the second resin 850 is greater than 40%. By combining the reinforcing layer 86 containing the second resin 850 with the functional layer 84, the problem that the impregnation of the resin 811 in the functional layer 84 into the reinforcing layer 86 is not uniform and sufficient after the non-resin 811 reinforcing layer 86 is combined with the functional layer 84 can be avoided. Further, the reinforcing layer 86 includes a single layer or two or more layers of fiber cloth, and the two or more layers of fiber cloth are adhered and cured by the second resin 850 after being laminated.

[0227] Furthermore, in some embodiments, a second curing agent and / or a second flame retardant are dispersed in the second resin 850 of the reinforcing layer 86. The second curing agent and the second flame retardant in the reinforcing layer 86 are similar to those in the reinforcing layer 85. Specifically, reference may be made to the above embodiments and will not be described in detail herein.

[0228] The composite layer further includes a second silicon-containing filler. The second silicon-containing filler in the reinforcing layer 86 is similar to that in the reinforcing layer 85. Specifically, reference may be made to the above embodiments and will not be described in detail herein.

[0229] The composite layer of the reinforcing layer 86 further includes second chopped fibers, which are provided in the functional layer 84 and can increase the strength uniformity of the reinforcing layer 86. The usage amount of the second chopped fibers is 0 to 15 wt% of the second silicon-containing filler, such as 2 wt%, 5 wt%, 7 wt%, 10 wt%, 12 wt% or 15 wt%. The second chopped fibers include one or more of carbon fibers, silicon carbide fibers, silicon nitride fibers, quartz fibers, aluminum silicate fibers, asbestos fibers, high-silica fibers, boron carbon fibers, and carbon nanotubes. The second chopped fibers have a length of 0.05 to 30 mm and a diameter of 1 to 15 μm.

[0230] The composite layer of the reinforcing layer 86 further includes a second high-temperature fusing agent and / or a second lubricant and / or a second ceramic precursor and / or a second heat-reflective filler 842 and / or a phase change material and / or a colorant. That is, the composite layer of the reinforcing layer 85 is substantially the same as the structure of the composite layer of the reinforcing layer 86, and the difference lies in that the melting point of the fiber matrix 810 of the reinforcing layer 86 is higher than that of the fiber matrix 810 of the reinforcing layer 85. The second high-temperature fusing agent, the second lubricant, the second ceramic precursor, the second heat-reflective filler 842, the phase change material, and the colorant in the reinforcing layer 86 are similar to those in the reinforcing layer 85. Specifically, reference may be made to the above embodiments and will not be described in detail herein.

[0231] Optionally, in some embodiments, the heat-resistant protective material 8 further includes a getter, which absorbs the combustible gas ejected from the pressure relief valve of the cell and is used to delay the thermal runaway of the battery. In some embodiments, the getter is filled in at least one of the reinforcing layer 85, the functional layer 84, and the reinforcing layer 86. In some other embodiments, the getter is provided between two adjacent layers of the reinforcing layer 85, the functional layer 84, and the reinforcing layer 86 to form a getter layer 82, or, as shown in FIG. 27, the getter is provided on the side away from the functional layer 84 of the reinforcing layer 85 to form a getter layer 82. Optionally, in some embodiments, the getter includes one or more of carbon molecular sieve, zeolite sieve, graphene, talc, and alumina.

[0232] Optionally, in some embodiments, referring to FIG. 28, the heat-resistant protective material 8 further includes a heat-insulating layer 83, which is provided on the side away from the functional layer 84 of the reinforcing layer 86 and is used to block the transmission of the temperature of the heat-receiving surface of the heat-resistant protective material 8 to the non-heat-receiving surface temperature. Optionally, in some embodiments, the heat-insulating layer 83 includes an aerogel coating or an aerogel felt.

[0233] Optionally, in some embodiments, the reinforcing layer 85 covers the entire functional layer 84, and the reinforcing layer 86 includes a plurality of sub-reinforcing layers 86 provided at intervals. Since the melting point of the fiber matrix 810 of the reinforcing layer 86 is higher than the melting point of the fiber matrix 810 of the reinforcing layer 85, the cost of the reinforcing layer 86 is also higher. In order to reduce the overall cost of the heat-resistant protective material 8, the reinforcing layer 86 is provided as a plurality of sub-reinforcing layers 86 provided at intervals, and during use, each sub-reinforcing layer 86 is provided corresponding to the pressure relief mechanism. Since the reinforcing layer 86 is provided only at the position corresponding to the pressure relief mechanism, the overall cost of the heat-resistant protective material 8 can be reduced.

[0234] Hereinafter, the heat-resistant protective material 8 provided by the present application will be described in combination with specific examples and comparative examples.

[0235] Example 1 In this example, a 7-layer fiber cloth was impregnated with resin and then laminated. As the curing conditions, first, compression molding was performed at a compression molding temperature of 140°C and a compression molding time of 30 minutes. Then, it was placed in an oven with a baking temperature of 150°C and a baking time of 2 hours. In another form, first, the heat-resistant protective material preform was semi-cured and then cured. Specifically, after the 7-layer fiber cloth was impregnated with resin, it was left standing at 25°C until the surface was dry (semi-cured), or compression molded at 70°C for 20 minutes / dried in an oven until the surface was dry (semi-cured). Then, the semi-cured heat-resistant protective material preforms were laminated and cured. As the curing conditions, first, compression molding was performed at a compression molding temperature of 150°C and a compression molding time of 20 minutes. Then, it was placed in an oven with a baking temperature of 180°C and a baking time of 1 hour.

[0236] The high-silica fiber cloth and quartz fiber cloth used in this example were purchased from Shaanxi Huate New Materials Co., Ltd., and the carbon fiber cloth was purchased from Shibang (Shanghai) Industry Co., Ltd.

[0237] The phenolic resin used in this example was purchased from Jinan Shengquan Group Co., Ltd., the benzoxazine resin was purchased from Chengdu Keyi Polymer Science and Technology Co., Ltd., the furfural acetone resin was purchased from Shandong Yongchuang Material Science and Technology Co., Ltd., and the epoxy resin was purchased from Guodu Chemical Industry (Kunshan) Co., Ltd.

[0238] In this Example 1, 13 samples were manufactured, namely Sample 1-1 to Sample 1-13 respectively.

[0239] Comparative Example 1 Comparative Example 1 of this application is substantially the same as the manufacturing method of Example 1. In this application, two comparative samples were manufactured, namely Comparative Sample 1-A and Comparative Sample 1-B respectively.

[0240] Performance Test (1) Bending Strength Test The test method for the flexural strength of the heat-resistant protective material adopts the national standard "GB / T 1449-2005 Test Method for Flexural Properties of Fiber Reinforced Plastics". The sample is manufactured to have a thickness of 1mm < h ≤ 3mm and a width of 15 ± 0.5mm. As the test equipment, a universal mechanical testing machine is used. Specifically, the test equipment shall adopt the test equipment as per Article 5 of the national standard "GB / T 1446-2005 General Principles for Test Methods of Fiber Reinforced Plastics Performance".

[0241] (2) Impact test with a hot air flow at 1500°C Fix the four sides of the heat-resistant protective material, apply a hot air flow at 1500°C to the heat-resistant protective material for a duration of 30s, and test whether the flame can pass through it. Here, flame penetration refers to the phenomenon that a naked flame appears on the back surface of the heat-resistant protective material when the flame ablates. Since the heat-resistant protective material contains a long fiber cloth, it will not be broken through during the test, but the flame can pass through.

[0242] For the test results, refer to Table 1. The volume ratio refers to the volume ratio in the fiber matrix composite layer.

[0243]

Table 1

[0244] As can be seen from Table 1 above, when the volume ratio of the fiber matrix is less than 50%, the thermal shock performance deteriorates, and the flame passes through when impacted by a hot air flow at 1500°C for 30s. The flexural strength of the heat-resistant protective material using uniaxial fabric is superior to that of the heat-resistant protective materials with other weaving methods. Also, the heat-resistant protective material without a fiber matrix only contains resin, but the thermal decomposition temperature of the resin is generally several hundred degrees, that is, it decomposes after several hundred degrees and cannot resist thermal shock. The flexural strength of the heat-resistant protective material manufactured using carbon fiber cloth is significantly superior to that of high silica fiber cloth, but its production cost is relatively high.

[0245] Example 2 In this example, polysilazane was used in the ceramic precursor slurry. The resin and polysilazane were mixed, and a fiber cloth was employed to immerse in the mixed solution of the resin and polysilazane. As for the curing conditions, first, compression molding was carried out at 60 °C for 30 min, then the temperature was raised to 140 °C and maintained for 30 min, and thereafter, it was placed in an oven and maintained at 156 °C for 1.5 h until it was completely cured.

[0246] The polysilazane resin and polyborosilazane resin adopted in this example were purchased from Anhui Aiyue Tower Silicon Oil Co., Ltd., and the resin and fiber cloth were purchased from the same manufacturer as in Example 1.

[0247] In this Example 2, six samples were manufactured, namely Sample 2-1 to Sample 2-6 respectively.

[0248] Comparative Example 2 Comparative Example 2 of this application is substantially the same as the manufacturing method of Example 2. In this application, five comparative samples were manufactured, namely Comparative Sample 2-A to Comparative Sample 2-E respectively.

[0249] Refer to Table 2 for the test results. The ratio of the ceramic precursor slurry is the ratio of the mass of the ceramic precursor slurry to the sum of the masses of the ceramic precursor slurry and the resin.

[0250]

Table 2A

[0251]

Table 2B

[0252] As can be seen from Table 1 and Table 2 above, the thermal shock performance of the heat-resistant protective material with the addition of the ceramic precursor is enhanced, and the flame can be prevented from passing through even when shocked by a hot air flow at 1500°C for 50 s. It can withstand thermal shock for a longer time compared to the heat-resistant protective material without the ceramic precursor. The thermal shock performance of the heat-resistant protective material is related to the content of the ceramic precursor slurry. When the ratio of the mass of the ceramic precursor slurry to the sum of the masses of the ceramic precursor slurry and the resin is less than 20%, the flame will pass through when shocked by a hot air flow at 1500°C for 50 s. Also, when the ratio of the mass of the ceramic precursor slurry to the sum of the masses of the ceramic precursor slurry and the resin is 50% or more, the flexural strength of the heat-resistant protective material is reduced.

[0253] Example 3 In this example, first, the method of Example 1 was adopted to manufacture the fiber resin composite semi-cured layer. Subsequently, the silicon-containing filler was uniformly sprayed on the surface of the fiber resin composite semi-cured layer, and then hot-pressed to cure. The hot-pressing temperature was 140°C, and the hot-pressing time was 30 min. During the hot-pressing process, some of the silicon-containing filler could enter the resin and the fiber cloth. Then, it was baked at 150°C for 2 h.

[0254] The silica aerogel adopted in this example was manufactured by our company using the sol-gel method. The mica powder was purchased from Anhui Gerui New Materials Science and Technology Co., Ltd. The ceramic fine powder, quartz powder, and white carbon black were purchased from Shanghai Huijing Asia Nano New Materials Co., Ltd. The resin and the fiber cloth were purchased from the same manufacturer as in Example 1.

[0255] In this Example 3, 15 samples were manufactured, namely Sample 3-1 to Sample 3-15 respectively.

[0256] Comparative Example 3 Comparative Example 3 of this application is substantially the same as the manufacturing method of Example 3. In this application, 6 comparative samples were manufactured, namely Comparative Sample 3-A to Comparative Sample 3-F respectively.

[0257] The test results refer to Table 3, and the content of the silicon-containing filler refers to the volume ratio of the silicon-containing filler to the fiber matrix.

[0258]

Table 3A

[0259]

Table 3B

[0260]

Table 3C

[0261] Example 4 In this example, first, the method of Example 1 was adopted to manufacture a fiber resin composite semi-cured layer. Subsequently, after mixing the silicon-containing filler and the high-temperature fusion agent (or the high-temperature fusion agent), it was uniformly sprayed onto the surface of the fiber resin composite semi-cured layer, and then hot-pressed to cure. The hot-pressing temperature was 140 °C, and the hot-pressing time was 30 min. During the hot-pressing process, some of the silicon-containing filler and the high-temperature fusion agent (or the high-temperature fusion agent) could enter the resin and the fiber cloth, and then it was baked at 150 °C for 2 h.

[0262] The talc, kaolin, and aluminum silicon powder adopted in this example were purchased from Shanghai Huijing Nano New Materials Co., Ltd., and the silicon-containing filler, resin, and fiber cloth were purchased from the same manufacturer as in Example 3.

[0263] In this Example 4, 12 samples were manufactured, namely Sample 4-1 to Sample 4-12 respectively. The silicon-containing filler and the high-temperature fusion agent were added to Sample 4-1 to Sample 4-8, and only the high-temperature fusion agent was added to Sample 4-9 to Sample 4-12.

[0264] Comparative Example 4 Comparative Example 4 of the present application is substantially the same as the manufacturing method of Example 4. In the present application, six comparative samples were manufactured, namely Comparative Sample 4-A to Comparative Sample 4-F, respectively.

[0265] Refer to Table 4-1 and Table 4-2 for the test results.

[0266]

Table 4-1A

[0267]

Table 4-1B

[0268] The study found that as the content of the high-temperature fusing agent increases, the bending strength also increases. However, when the content of the high-temperature fusing agent is greater than 40 wt% as in Comparative Sample 4-B, for example, the wettability of the silicon-containing filler and the high-temperature fusing agent with the resin becomes poor, and it is further found that they will become stratified.

[0269]

Table 4-2

[0270] As can be seen from Table 4-1 and Table 4-2 above, the thermal shock performance of the heat-resistant protective material with the addition of the high-temperature fusing agent is enhanced, and it is possible to prevent the flame from passing through even when it is shocked by a hot air flow at 1500°C for 50 s. It can withstand thermal shock for a longer time compared to the heat-resistant protective material without the high-temperature fusing agent. Whether the content of the high-temperature fusing agent is too high or too low will affect the thermal shock performance of the heat-resistant protective material.

[0271] Example 5 In this example, first, the method of Example 1 was adopted to manufacture a fiber resin composite layer. Subsequently, after mixing a silicon-containing filler and a lubricant, it was uniformly sprayed on the surface of the fiber resin composite layer, and then hot-pressed to cure. The hot-press temperature was 140 °C, the hot-press time was 30 min, and during the hot-press process, some of the silicon-containing filler could enter the resin and the fiber cloth. Then, it was baked at 150 °C for 2 h.

[0272] The talc adopted in this example was purchased from Shanghai Huijing Nano New Materials Co., Ltd., and the paraffin wax, polyethylene wax, and polyamide wax were purchased from Shanghai Yiba Chemical Raw Materials Co., Ltd. The silicon-containing filler, resin, and fiber cloth were purchased from the same manufacturer as in Example 3.

[0273] In this Example 5, four samples were manufactured, namely Sample 5-1 to Sample 5-4 respectively.

[0274] Comparative Example 5 Comparative Example 5 of this application is substantially the same as the manufacturing method of Example 5. In this application, three comparative samples were manufactured, namely Comparative Sample 5-A to Comparative Sample 5-C respectively.

[0275] For the test results, refer to Table 5. The content of the lubricant in the silicon-containing filler refers to the mass ratio of the lubricant to the silicon-containing filler.

[0276]

Table 5A

[0277]

Table 5B

[0278] Studies have shown that as the lubricant content increases, the bending strength also increases. However, when the lubricant content is greater than 40 wt% as in Comparative Sample 5-B, for example, it has been further found that the silicon-containing filler or the lubricant has poor wettability with the resin and will become stratified.

[0279] Example 6 In this example, the resin and the silicon-containing filler are mixed according to the ratio. The silicon-containing filler can be added in multiple portions so as to be uniformly mixed, and after being uniformly mixed, it is cured. The curing conditions are the same as those in Example 1.

[0280] The selection and purchase of raw materials are the same as those in Example 3.

[0281] In this Example 6, 13 samples are manufactured, namely Sample 6-1 to Sample 6-13 respectively.

[0282] Comparative Example 6 Comparative Example 6 of this application is substantially the same as the manufacturing method of Example 6. In this application, two comparative samples are manufactured, namely Comparative Sample 6-A and Comparative Sample 6-B respectively.

[0283] The test results are shown in Table 6. The ratio of the resin to the silicon-containing filler is a mass ratio.

[0284]

Table 6A

[0285]

Table 6B

[0286] Example 7 In this example, a silicon-containing filler and a high-temperature fusion agent are mixed, and the mixture of the silicon-containing filler and the high-temperature fusion agent is added to the resin and uniformly mixed. The silicon-containing filler and the high-temperature fusion agent can be added in multiple portions so as to uniformly mix the added materials. After uniform mixing, it is cured, and the curing conditions are the same as those in Example 1.

[0287] The selection and purchase of raw materials are the same as those in Example 4.

[0288] In this Example 7, 13 samples are manufactured, namely Sample 7-1 to Sample 7-13 respectively.

[0289] For the test results, refer to Table 7. The content of the high-temperature fusion agent in the silicon-containing filler refers to the mass ratio of the high-temperature fusion agent to the silicon-containing filler, and the ratio of the resin to the silicon-containing filler is a mass ratio.

[0290]

Table 7A

[0291]

Table 7B

[0292] As can be seen from the comparison with Sample 6-3 in Table 7 and Table 6, after adding the high-temperature fusion agent, the flexural strength of the heat-resistant protective material is significantly enhanced.

[0293] Example 8 In this example, after uniformly mixing the silicon-containing filler and the lubricant, the silicon-containing filler and the lubricant are added to the resin, uniformly mixed, and then cured. The curing conditions are the same as those in Example 1. Since it does not contain a heat-resistant fiber cloth, regarding the usage amount of the lubricant, talc accounts for 5 to 40 wt% of the amount of the silicon-containing filler, and paraffin wax, polyethylene wax, etc. account for 3 to 10 wt% of the amount of the silicon-containing filler. However, since paraffin wax and polyethylene wax have a low melting point, if the amount is large, it will affect the thermal shock resistance.

[0294] The selection and purchase of raw materials are the same as those in Example 5.

[0295] In this Example 8, 10 samples are manufactured, namely Sample 8-1 to Sample 8-10 respectively.

[0296] Comparative Example 8 Comparative Example 8 of this application is substantially the same as the manufacturing method of Example 8. In this application, 3 comparative samples are manufactured, namely Comparative Sample 8-A, Comparative Sample 8-B, and Comparative Sample 8-C respectively.

[0297] For the test results, refer to Table 8. The content of the lubricant in the silicon-containing filler refers to the mass ratio of the lubricant to the silicon-containing filler, and the ratio of the resin to the silicon-containing filler is the mass ratio.

[0298]

Table 8A

[0299]

Table 8B

[0300] As can be seen from the comparison between Sample 8-2 and 8-3 in Table 8 and Sample 6-3 in Table 6, after adding the lubricant, the bending strength of the heat-resistant protective material is significantly enhanced.

[0301] Example 9 In this example, after uniformly mixing the silicon-containing filler and the lubricant, the silicon-containing filler and the lubricant were added to the resin, uniformly mixed, and then cured. The curing conditions were the same as those in Example 2. Since no heat-resistant fiber cloth was included, regarding the amount of the lubricant used, talc accounted for 5 to 40 wt% of the amount of the silicon-containing filler, and paraffin wax, polyethylene wax, etc. accounted for 3 to 10 wt% of the amount of the silicon-containing filler. However, since paraffin wax and polyethylene wax have a low melting point, if the amount is large, it will affect the thermal shock resistance.

[0302] The selection and purchase of raw materials were the same as those in Example 2 and Example 3.

[0303] In this Example 9, 28 samples were manufactured, namely Sample 9-1 to Sample 9-28 respectively.

[0304] Comparative Example 9 Comparative Example 9 of the present application was substantially the same as the manufacturing method of Example 9. In the present application, Comparative Sample 9-A was manufactured.

[0305] For the test results, refer to Table 9. The content of the ceramic precursor slurry is the ratio of the ceramic precursor slurry to the sum of the masses of the ceramic precursor slurry and the resin, and the ratio of the resin to the silicon-containing filler is a mass ratio.

[0306]

Table 9A

[0307]

Table 9B

[0308]

Table 9C

[0309]

Table 9D

[0310] As can be seen from Table 6 and Table 9 above, the thermal shock performance of the heat-resistant protective material added with the ceramic precursor is enhanced and it does not break even when impacted by a hot air flow at 1500 °C for 50 s, and it can withstand thermal shock for a longer time compared to the heat-resistant protective material without the ceramic precursor.

[0311] Example 10 In this example, the resin, the silicon-containing filler, and the chopped fibers are mixed according to the ratio. The silicon-containing filler and the chopped fibers may be added after being premixed, or may be added separately in multiple times. The addition order is not limited. After uniformly mixing them, they are cured, and the curing conditions are the same as those in Example 1.

[0312] The chopped carbon fibers used in this example are purchased from Jiangxi Shuobang New Material Science and Technology Co., Ltd., the chopped silicon carbide fibers are purchased from Hunan Rui New Materials Co., Ltd., and the other materials are purchased in the same way as in Example 6.

[0313] In this Example 10, 8 samples are manufactured, which are Sample 10-1 to Sample 10-8 respectively.

[0314] Comparative Example 10 Comparative Example 10 of this application is substantially the same as the manufacturing method of Example 10. In this application, 3 comparative samples are manufactured, which are Comparative Sample 10-A to Comparative Sample 10-C respectively.

[0315] For the test results, refer to Table 10. The ratio of the resin to the silicon-containing filler is the mass ratio.

[0316]

Table 10A

[0317]

Table 10B

[0318] As can be seen from Table 10, the flexural strength of the heat-resistant protective material increases after appropriately adding chopped fibers. However, if the content of the chopped fibers is too high, for example, when the mass ratio of the chopped fibers to the silicon-containing filler is greater than 15%, the flexural strength of the heat-resistant protective material decreases. This is presumably because the chopped fibers are difficult to disperse and tend to aggregate, and the joints of the chopped fibers may become weak points during the thermal shock process.

[0319] Example 11 In this example, the functional layer was manufactured according to the method of Example 10, the reinforcing layer was manufactured according to the method of Example 1, or a fiber cloth was adopted as the reinforcing layer, and then the functional layer and the reinforcing layer were laminated and combined by hot pressing.

[0320] The purchase sources of the raw materials are the same as those in Example 1 and Example 6.

[0321] In this Example 11, five samples were manufactured, namely Sample 11-1 to Sample 11-5 respectively.

[0322] Refer to Table 11 for the test results.

[0323]

Table 11

[0324] Example 12 In this example, the functional layer was manufactured according to the method of Example 10, the reinforcing layer / reinforcement layer was manufactured according to the method of Example 1, or a pure fiber cloth was adopted as the reinforcing layer / reinforcement layer, and then the functional layer was sandwiched between the reinforcement layer and the reinforcing layer, laminated, and combined by hot pressing.

[0325] The purchase sources of the raw materials are the same as those in Example 1 and Example 6.

[0326] In Example 12, six samples were manufactured, namely Sample 12-1 to Sample 12-6.

[0327] Refer to Table 12 for the test results.

[0328]

Table 12A

[0329]

Table 12B

[0330] Each of the technical features of the embodiments described above can be arbitrarily combined. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments have been described. However, as long as these combinations of technical features do not conflict, they should all be regarded as falling within the scope described in this specification.

[0331] The embodiments described above only represent some embodiments of the present application. Although the description is specific and detailed, it should not be understood as a limitation to the scope of the claims. It should be pointed out that those skilled in the art can make some modifications and improvements without departing from the concept of the present application, and all of these modifications and improvements belong to the protection scope of the present application. Therefore, the protection scope claimed by the present application shall be based on the scope of the claims.

Explanation of Reference Numerals

[0332] 1 Vehicle, 2 Battery, 6 Battery Cell, 8 Heat-Resistant Protective Material, 9 Thermal Resistance Layer, 20 housing, 6a first battery cell, 6b second battery cell, 61 electrode assembly, 62 housing, 63 electrode terminal, 64 connection member, 65 decompression mechanism, 66 thermal management component, 67 heat insulation component, 68 first wall, 69 second wall, 81 fiber resin composite layer, 810 fiber matrix, 811 resin, 82 getter layer, 83 heat insulation layer, 84 functional layer, 841 first resin, 842 filler, 85 reinforcement layer, 850 second resin, 86 reinforcing layer 201 first housing part / top cover, 202 second housing part / bottom wall, 203 accommodation space, 621 case, 622 end cover, 631 positive electrode terminal, 632 negative electrode terminal, 661 vulnerable area

Claims

1. A heat-resistant protective material comprising a functional layer, wherein the functional layer comprises a first resin and a filler dispersed in the first resin.

2. The mass content of carbon element in the first resin is greater than 40%, the filler is chopped fiber, the volume ratio of the chopped fiber in the functional layer is 50-80%, and the chopped fiber comprises one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, boron carbon fiber, carbon nanotube, or the filler is a first heat-reflective filler, the volume ratio of the first heat-reflective filler in the functional layer is 45-75%, and the first heat-reflective filler comprises one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium. The heat-resistant protective material according to claim 1.

3. The mass content of carbon element in the first resin is greater than 40%, the filler comprises a first silicon-containing filler, and the weight ratio of the first resin to the first silicon-containing filler is 1:3 to 1:

1. The heat-resistant protective material according to claim 1.

4. The first silicon-containing filler comprises one or more combinations of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, and talc. The heat-resistant protective material according to claim 3.

5. The first silicon-containing filler comprises silica aerogel powder and mica powder, and the mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:

1. The heat-resistant protective material according to claim 3.

6. The first silicon-containing filler comprises silica and aluminum oxide, the usage amount of the silica is 50-80 wt% of the first silicon-containing filler, and the usage amount of the aluminum oxide is 10-30 wt% of the first silicon-containing filler. The heat-resistant protective material according to claim 3.

7. The filler further comprises a first high-temperature fusing agent, and the usage amount of the first high-temperature fusing agent is 10 wt% to 40 wt% of the first silicon-containing filler. The first high-temperature fusion agent contains one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, and aluminum silicon powder, and the material of the first high-temperature fusion agent is different from the material of the first silicon-containing filler. The heat-resistant protective material according to claim 3.

8. The filler further contains a first lubricant, and the usage amount of the first lubricant is 10 to 40 wt% of the first silicon-containing filler. The heat-resistant protective material according to claim 3.

9. The functional layer further contains a first ceramic precursor, and the volume ratio of the first ceramic precursor to the sum of the volumes of the first ceramic precursor and the first resin is less than 50%, or the mass ratio of the first ceramic precursor to the sum of the masses of the first ceramic precursor and the first resin is less than 50%. The heat-resistant protective material according to claim 3.

10. The first ceramic precursor contains one or more of polysilazane resin, polyborosilazane resin, and polycarbosilane resin. The heat-resistant protective material according to claim 9.

11. The filler further contains chopped fibers, and the usage amount of the chopped fibers is 0 to 15 wt% of the first silicon-containing filler. The chopped fibers contain one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, boron carbon fiber, and carbon nanotube. The chopped fibers have a length of 0.05 to 30 mm and a diameter of 1 to 15 μm. The heat-resistant protective material according to claim 3.

12. The filler further contains a first heat-reflective filler, and the usage amount of the first heat-reflective filler is 0 to 5 wt% of the first silicon-containing filler. The first heat-reflective filler contains one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium. The heat-resistant protective material according to claim 3.

13. The heat-resistant protective material further includes a reinforcing layer provided by laminating with the functional layer, and the thickness ratio of the functional layer to the reinforcing layer is (8 to 10):(1 to 4). The heat-resistant protective material according to claim 1.

14. The reinforcing layer is a fiber matrix, or the reinforcing layer includes a fiber matrix and a second resin, and the second resin is dispersed in voids within and / or on the surface of the fiber matrix to form a composite layer. The heat-resistant protective material according to claim 13, characterized in that.

15. When the reinforcing layer includes a fiber matrix and a second resin, the mass content of carbon element in the second resin is greater than 40%. The fiber matrix includes fiber cloth and / or fiber felt, and the fibers of the fiber matrix include one or more of carbon fiber, silicon carbide fiber, silicon nitride fiber, quartz fiber, aluminum silicate fiber, asbestos fiber, high silica fiber, boron carbon fiber, and carbon nanotube. The heat-resistant protective material according to claim 14, characterized in that.

16. The first resin includes one or more combinations of phenol resin, furfural acetone resin, benzoxazine resin, furan resin, polyurea, and phenol-modified epoxy resin, and / or the second resin includes one or more combinations of phenol resin, furfural acetone resin, benzoxazine resin, furan resin, polyurea, and phenol-modified epoxy resin. The heat-resistant protective material according to claim 14, characterized in that.

17. A first viscosity modifier is dispersed in the first resin, and the usage amount of the first viscosity modifier is 1 to 10% of the volume of the first resin, and / or A first curing agent is dispersed in the first resin, and / or A first flame retardant is dispersed in the first resin, and the usage amount of the first flame retardant is 5 to 40% of the mass of the first resin, and / or A second viscosity modifier is dispersed in the second resin, and the usage amount of the second viscosity modifier is 1 to 10% of the volume of the second resin, and / or A second curing agent is dispersed in the second resin, and / or A second flame retardant is dispersed in the second resin, and the usage amount of the second flame retardant is 5 to 40% of the mass of the second resin. The heat-resistant protective material according to claim 14, characterized in that.

18. The reinforcing layer includes a fiber matrix and a second resin, and a phase change material is further dispersed in the second resin. The usage amount of the phase change material is 5% to 20% of the volume of the fiber matrix. The heat-resistant protective material according to claim 14, characterized in that.

19. The fiber matrix includes a fiber cloth, and the fiber cloth is one or more of a fiber twill fabric, a fiber satin fabric, a fiber uniaxial fabric, and a fiber multi-axial fabric. The heat-resistant protective material according to claim 14, characterized in that.

20. The reinforcing layer includes a fiber matrix and a second resin, and the reinforcing layer further includes a second ceramic precursor. The ratio of the volume of the second ceramic precursor to the sum of the volumes of the second ceramic precursor and the second resin is less than 50%, or the ratio of the mass of the second ceramic precursor to the sum of the masses of the second ceramic precursor and the second resin is less than 50%. The heat-resistant protective material according to claim 14, characterized in that.

21. The second ceramic precursor includes one or more of a polysilazane resin and a polyborosilazane resin. The heat-resistant protective material according to claim 20, characterized in that.

22. The fiber matrix includes a first fiber matrix and a second fiber matrix. The second resin is dispersed in the voids of the first fiber matrix and / or covers two opposite surfaces of the first fiber matrix to form a first composite layer. The second ceramic precursor is dispersed in the voids of the second fiber matrix and / or covers two opposite surfaces of the second fiber matrix to form a second composite layer. The first composite layer and the second composite layer are provided in a laminated manner to form a laminated structure, or Two of the first composite layers sandwich at least one of the second composite layers to form a laminated structure, or Two of the second composite layers sandwich at least one of the first composite layers to form a laminated structure. The heat-resistant protective material according to claim 20, characterized in that.

23. The mixture of the second resin and the second ceramic precursor is dispersed in the voids of the fiber matrix and / or covers two opposite surfaces of the fiber matrix. The heat-resistant protective material according to claim 20, characterized in that.

24. The second ceramic precursor is applied to one surface of the composite layer or to two opposite surfaces of the composite layer. The heat-resistant protective material according to claim 20, characterized in that.

25. The reinforcing layer includes a fiber matrix and a second resin. The reinforcing layer further includes a second silicon-containing filler. The second silicon-containing filler occupies 40 to 70% of the volume of the fiber matrix. The heat-resistant protective material according to claim 14, characterized in that.

26. The second silicon-containing filler includes one or a combination of silica aerogel powder, quartz powder, mica powder, ceramic fine powder, white carbon black, wollastonite, montmorillonite, talc. The heat-resistant protective material according to claim 25, characterized in that.

27. The second silicon-containing filler includes silica aerogel powder and mica powder. The mass ratio of the silica aerogel powder to the mica powder is 1:3 to 1:

1. The heat-resistant protective material according to claim 25, characterized in that.

28. The second silicon-containing filler includes silica and aluminum oxide. The amount of silica used is 50 to 80 wt% of the second silicon-containing filler. The amount of aluminum oxide used is 10 to 30 wt% of the second silicon-containing filler. The heat-resistant protective material according to claim 25, characterized in that.

29. The second silicon-containing filler is applied to the surface of the composite layer or embedded in the second resin. The heat-resistant protective material according to claim 25, characterized in that.

30. The reinforcing layer further includes a second high-temperature fusing agent. The amount of the second high-temperature fusing agent used is 10 wt% to 40 wt% of the second silicon-containing filler. The second high-temperature fusing agent includes one or more of talc, wollastonite, mica powder, kaolin, barium sulfate, aluminum silicon powder. The material of the second high-temperature fusing agent is different from the material of the second silicon-containing filler. The heat-resistant protective material according to claim 25, characterized in that.

31. The reinforcing layer further includes a second lubricant. The amount of the second lubricant used is 10 to 40 wt% of the second silicon-containing filler. The heat-resistant protective material according to claim 25, wherein the second lubricant contains one or a combination of polyamide wax, polyethylene wax, and paraffin wax.

32. The reinforcing layer further contains a second heat-reflective filler, and the second heat-reflective filler is 5 to 30 wt% of the second silicon-containing filler. The heat-resistant protective material according to claim 25, wherein the second heat-reflective filler contains one or more of oxides or nitrides of titanium, iron, aluminum, zinc, lanthanum, and cerium.

33. The reinforcing layer contains a fiber matrix and a second resin, the reinforcing layer further contains a colorant, and the colorant contains one or more of carbon black, titanium white, iron black, oil-based color concentrate, and transition metal coloring ion oxides. The heat-resistant protective material according to claim 14.

34. The heat-resistant protective material further includes a getter, the getter is filled in the functional layer and / or the reinforcing layer, or the getter is provided between the functional layer and the reinforcing layer to form a getter layer. The heat-resistant protective material according to claim 13.

35. The heat-resistant protective material further includes a heat-insulating layer, and the heat-insulating layer is provided on a side away from the reinforcing layer of the functional layer. The heat-resistant protective material according to claim 13.

36. The heat-resistant protective material according to claim 35, wherein the heat-insulating layer includes an aerogel coating or an aerogel felt.

37. A battery comprising the heat-resistant protective material according to any one of claims 1 to 36.

38. A battery cell provided with a pressure reducing mechanism on a first wall. The battery according to claim 37, wherein the heat-resistant protective material and the pressure reducing mechanism are provided opposite to each other.

39. A plurality of battery cells including adjacent first battery cells and second battery cells arranged along a first direction. The battery according to claim 37, wherein the heat-resistant protective material is provided between the first battery cell and the second battery cell.

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