Novel composite material fireproof heat insulation pad

Abstract

The utility model discloses a novel fireproof heat insulation pad made of composite materials. Comprising ceramic microporous silicon foam, a double-sided flame-retardant adhesive layer, a flame-retardant polyimide thermosetting film and a microporous nano heat-resisting sheet, one surface of the double-sided flame-retardant adhesive layer is coated with flame-retardant silica gel, and the other surface of the double-sided flame-retardant adhesive layer is a PET double-sided adhesive tape with a strong and weak surface coated with flame-retardant acrylic acid; the micropore nanometer heat insulation sheet is packaged in the flame-retardant polyimide thermosetting film in a vacuum hot pressing mode, the double-face flame-retardant adhesive layers are attached to the two end faces of the flame-retardant polyimide thermosetting film respectively, and the ceramic micropore silicon foam is arranged on the other end faces of the double-face flame-retardant adhesive layers. According to the utility model, the problems of low heat resistance, no compression fatigue resistance, no fire prevention, efficient bonding of various surface energy materials, no flame retardance of a packaging film, poor sealing performance and the like of a heat insulation material in a soft package battery of an existing new energy automobile can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of fireproof and heat-insulating pads, in particular to a fireproof and heat-insulating pad made of a new composite material. Background Art

[0002] With the continuous iteration and upgrading of power battery technologies, the energy density of power batteries has been increasing continuously, the structural design has become more perfect, and the cruising range has entered the era of long cruising range of more than 1000 km. New energy vehicles are gradually replacing fuel vehicles, and their market share in the Chinese domestic sales has exceeded 50% in 2024. The utility model mainly elaborates on fireproof and heat insulation between soft-pack battery cells in battery assembly, especially in soft-pack battery packs, to physically block from the dimension of the smallest ignition unit. At the same time, it takes into account the buffering and protection of the periodic expansion stress during the charge and discharge of soft-pack battery cells under normal working conditions, protects the battery from mechanical pressure, and assembles heat-insulating materials with low thermal conductivity between the battery cells, which can effectively inhibit the spread of heat.

[0003] The first-generation heat-insulating materials on the market are products such as silicone and polyurethane foam. These products have good compression resilience and normal-temperature heat insulation, but their flame retardancy and heat insulation at high temperatures are difficult to achieve the effect of inhibiting the spread of thermal runaway. The second-generation products currently used on the market, such as pre-oxidized fiber aerogel felt, glass fiber aerogel felt, and ceramic fiber aerogel felt, have a lower thermal conductivity, and the fireproof and heat-insulating effect has been greatly improved. However, due to the limit of the substrate's maximum heat resistance, it is difficult to cover ultra-high temperature heat-insulating scenarios exceeding 1000°C. Moreover, after the temperature exceeds 500°C, the thermal conductivity also rises from 0.020 W / mk at normal temperature to 0.068 W / mk, and the heat-insulating effect is greatly reduced. At the same time, the compression resilience of aerogel is worse than that of foam, and it is difficult to meet the buffering of the periodic expansion stress during the charge and discharge of soft-pack batteries when used alone. Content of the Utility Model

[0004] Aiming at the deficiencies existing in the above-mentioned prior art, the purpose of the utility model is to provide a fireproof and heat-insulating pad made of a new composite material, which can solve the problems such as low heat resistance, poor compression fatigue resistance, non-fireproof, high-efficiency bonding of various surface energy materials, and poor flame retardancy and sealing performance of the encapsulation film in the heat-insulating materials of soft-pack batteries of existing new energy vehicles.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A fireproof and heat-insulating pad made of a new composite material, comprising a ceramized microporous silica foam, a double-sided flame-retardant adhesive layer, a flame-retardant polyimide thermosetting film, and a microporous nano heat-insulating sheet. One side of the double-sided flame-retardant adhesive layer is coated with flame-retardant silica gel, and the other side of the double-sided flame-retardant adhesive layer is a PET double-sided tape with a strong and weak surface coated with flame-retardant acrylic acid. The microporous nano heat-insulating sheet is encapsulated in the flame-retardant polyimide thermosetting film by means of vacuum hot pressing. The double-sided flame-retardant adhesive layer is respectively adhered to both end faces of the flame-retardant polyimide thermosetting film, and the ceramized microporous silica foam is arranged on the other end face of the double-sided flame-retardant adhesive layer.

[0007] Preferably, the ceramized microporous silica foam has a density between 350 and 500 kg / m³, a 25% compression resilience in the range of 65 kPa to 120 kPa, a thermal conductivity lower than 0.06 W / (m·K), a bulk flame retardancy rating of V0, can form a ceramic layer on the surface at high temperatures above 450 °C, and can withstand a maximum temperature of 1000 °C without cracking within 10 minutes.

[0008] Preferably, the bulk material of the double-sided flame-retardant adhesive layer has a flame retardancy rating of VTM-0. At the same time, the flame-retardant silica gel coated on the double-sided flame-retardant adhesive layer is bonded to the ceramized microporous silica foam, and the PET double-sided tape of the double-sided flame-retardant adhesive layer is bonded to the flame-retardant polyimide thermosetting film.

[0009] Preferably, the nano powder particles used in the microporous nano heat-insulating sheet have a particle size of about 30 nm, an overall density of 300 kg / m³ to 450 kg / m³, a thermal conductivity lower than 0.021 W / (m·K) at room temperature, and a thermal conductivity lower than 0.035 W / (m·K) in a high-temperature environment of 800 °C.

[0010] Due to the adoption of the above scheme, the present utility model has the following advantages:

[0011] 1. The fireproof and heat-insulating pad made of the new composite material can provide good characteristics of resistance to repeated charge and discharge voltage compression fatigue for soft-pack batteries. At the same time, the foam used has a bulk flame retardancy rating of V0, can form a ceramic layer on the surface at high temperatures above 450 °C, and can withstand a maximum temperature of 1000 °C without cracking within 10 minutes. The ceramized microporous silica foam can provide better flame retardancy and high-temperature compression resistance, avoiding the process of ordinary foam melting, carbonizing and catching fire at high temperatures. At the same time, the protection characteristics of the ultra-high temperature and low thermal conductivity provided by the nano heat-insulating board can effectively isolate the temperature transfer between the battery cells and effectively prevent the occurrence of heat spread.

[0012] 2. The fireproof and heat-insulating pad made of the novel composite material bonds materials with different interfaces through a double-sided flame-retardant adhesive layer of flame-retardant silica gel / acrylic PET, which can eliminate the process of applying silica gel treatment agent, making it easier to achieve automated lamination in production and the paste more firm, and not easily causing structural failure during repeated extrusion, resulting in shear misalignment of the foam and the nano heat-insulating board. Using flame-retardant tape reduces the risk of glue melting and carbonizing to catch fire under high-temperature conditions, and overall improves the fire resistance of the entire heat-insulating pad.

[0013] 3. The fireproof and heat-insulating pad made of the novel composite material has a breakdown voltage of more than 100 KV / mm and a volume resistivity of more than 1×10¹⁷ Ω·cm in the flame-retardant polyimide thermosetting film in the product structure, far exceeding that of PET thermosetting films, reducing the risk of breakdown between battery cells. Combining with the self-extinguishing property of polyimide, the smoke emission rate is extremely low, and the char residue rate exceeds 50% under high-temperature conditions. It is a good flame retardant and heat insulator.

[0014] 4. The fireproof and heat-insulating pad made of the novel composite material has a large degree of freedom in the structural thickness matching, and can be adjusted according to the customer's design space and the requirements of thermal runaway temperature control. The thickness range of the ceramicized microporous silica foam is 0.6 mm to 4 mm, the thickness range of the double-sided flame-retardant adhesive layer of flame-retardant silica gel / acrylic PET is 0.05 mm to 0.10 mm, the thickness range of the flame-retardant polyimide thermosetting film is 0.03 mm to 0.08 mm, the thickness range of the nano heat-insulating board is 1.0 mm to 3.0 mm, the 7-layer stack thickness is above 2.36 mm, and the initial compression rate of the ceramicized microporous silica foam is between 20% and 30%. By adjusting the initial thickness of the ceramicized microporous silica foam and the initial thickness of the nano heat-insulating board, it can adapt to a telecom gap of 2 mm or more. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural cross-sectional view of an embodiment of the present utility model.

[0016] Figure 2 is a perspective view of an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0018] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, the meaning of "a plurality of" is two or more, unless otherwise specifically defined.

[0019] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection. It may be a mechanical connection or an electrical connection. It may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0020] Such as Figure 1 and Figure 2As shown in the figure, a fireproof and heat-insulating pad made of a new type of composite material provided in this embodiment includes a ceramized microporous silica foam 1, a double-sided flame-retardant adhesive layer 2, a flame-retardant polyimide thermosetting film 3, and a microporous nano heat-insulating sheet 4. Specifically, a microporous nano heat-insulating board 4 of appropriate size is cut by a wire cutting machine, a flame-retardant polyimide thermosetting film 3 of appropriate size is cut by a cutting machine, and a three-layer structure of the flame-retardant polyimide thermosetting film 3, the microporous nano heat-insulating board 4, and the flame-retardant polyimide thermosetting film 3 is fixed by a jig and placed in a vacuum hot press. The process is set as follows: the hot press plate is at 90°C to 150°C, the preheating time is 10 to 20 s, after the hot press plate is adhered, vacuum exhaust is carried out for 20 to 60 s, and the pressure holding time is 20 to 60 s. After forming, it is cut by a cutting machine so that the overall sealing effect and dimensional tolerance of the flame-retardant polyimide thermosetting film encapsulating the microporous nano heat-insulating sheet meet the finished product requirements, and a polyimide-encapsulated nano heat-insulating sheet is made. The roll-shaped ceramized microporous silica foam 1 is adhered to one side of the double-sided flame-retardant adhesive layer 2, roll-pressed and attached to the flame-retardant silica gel surface in an oven within the range of 40°C to 60°C, cut into sheets, and then a semi-finished product of appropriate size (ceramized microporous silica foam with an adhesive) is punched out by a hydraulic press. The three-layer semi-finished products of the ceramized microporous silica foam with an adhesive, the polyimide-encapsulated nano heat-insulating sheet, and the ceramized microporous silica foam with an adhesive are laminated into a fireproof and heat-insulating pad by means of manual gluing.

[0021] Furthermore, the particle size of the nano powder particles used in the microporous nano heat-insulating sheet 4 of this embodiment is about 30 nm, the overall density is about 300 kg / m³ to 450 kg / m³, the thermal conductivity at room temperature is lower than 0.021 W / (m*K), and the thermal conductivity at 800°C high temperature environment is lower than 0.035 W / (m*K). It can withstand a high temperature of 1200°C for a short time and 1000°C for a long time. It is the core heat-insulating material of the fireproof and heat-insulating pad, and the flame-retardant grade can reach A1 level. Compared with ceramic fiber aerogel of the same thickness, the overall tensile strength is increased by 120%, and the 30% compressive strength is increased by 10 times. The thermal conductivity at 800°C is only 50% of that of aerogel. As the core heat-insulating material, it can greatly improve the heat insulation ability per unit thickness. Moreover, by using a gas-phase silica content as high as 50% to 80%, adding a small amount of alumina and silicon carbide for modification, the fire resistance and pressing compactness of the product can be further improved. Adding a small amount of glass fiber as the skeleton layer can increase the overall strength and stiffness of the product.

[0022] Furthermore, the double-sided flame-retardant adhesive layer 2 of this embodiment has excellent flame retardancy while maintaining good bonding performance, and the body material can reach the VTM-0 flame-retardant grade. At the same time, the specific structure is that flame-retardant silica gel and flame-retardant acrylic glue are respectively coated on both sides of the PET substrate. Among them, due to the low surface energy of the surface skin of the ceramized silica foam, it is not easy to bond. In the production process, an organosilicon surface treatment agent is usually used to treat its surface to achieve bonding with the acrylic tape. The double-sided flame-retardant adhesive layer 2 can be bonded through the flame-retardant silica gel, which can effectively solve the problem of inconsistent bonding surfaces and eliminate the process of brushing the silica treatment agent. The best bonding strength can be achieved during storage after cold pressing and pasting. When peeled off, it will directly damage the surface of the ceramized silica foam, and the bonding effect is good. The other side is bonded to the flame-retardant polyimide thermosetting film, and the bonding strength can reach more than 8 N / cm within 20 minutes, making the overall structure of the product stable and reliable.

[0023] Furthermore, the ceramized microporous silica foam 1 of this embodiment is selected with a body flame-retardant grade of V0, which can form a ceramic layer on the surface at a high temperature of more than 450 °C, and can withstand a maximum temperature of 1000 °C without cracking within 10 minutes. It can provide better flame retardancy and high-temperature compression resistance, avoiding the process of ordinary foam melting, carbonizing and catching fire at high temperatures. At the same time, the super-high-temperature and low-thermal-conductivity protection characteristics provided by the nano-insulation board can effectively isolate the temperature transfer between the battery cells and effectively prevent the occurrence of thermal spread.

[0024] Furthermore, the flame-retardant polyimide thermosetting film 3 of this embodiment has a breakdown voltage of more than 100 KV / mm and a volume resistivity of more than 1×10¹⁷ Ω·cm, far exceeding that of PET-based thermosetting films, reducing the risk of breakdown between battery cells. Polyimide has self-extinguishing properties, a very low smoke generation rate, and a char residue rate of more than 50% under high-temperature conditions, and it is a good flame retardant and heat insulator.

[0025] Furthermore, the production process of this embodiment can be automated through the configuration of automatic blanking, pneumatic robotic arms, and vision positioning systems to improve production efficiency. The production efficiency using automated equipment is one mold in 60 seconds. Assuming one mold is 650 mm * 650 mm, 5 to 6 heat insulation sheets suitable for 590 soft-pack battery cells can be produced. The maximum daily production capacity of a single automated equipment is 8640 pieces. An electric vehicle is equipped with about 384 high-performance soft-pack batteries, and the maximum daily production capacity of a single automated equipment can be used by about 22 electric vehicles.

[0026] Furthermore, by equipping with the fireproof and heat-insulating pad made of a new type of composite material in this embodiment, at a minimum thickness of 2.36 mm, when the hot surface is maintained at 1000 °C, the cold surface can be kept below 250 °C within 5 minutes and below 280 °C within 10 minutes. The time when the soft-pack battery cell truly reaches the extreme high temperature is very short, and the temperature will drop below 400 °C within 3 minutes. The fireproof and heat-insulating pad can effectively delay the heat spread and control the thermal runaway within the range of a single battery cell, meeting the current requirements for automotive thermal runaway safety protection.

[0027] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A fireproof and heat-insulating pad made of a new type of composite material, characterized in that: It includes ceramized micro-porous silica foam, double-sided flame-retardant adhesive layer, flame-retardant polyimide thermosetting film and micro-porous nano heat insulation sheet. One side of the double-sided flame-retardant adhesive layer is coated with flame-retardant silica gel, and the other side of the double-sided flame-retardant adhesive layer is a PET double-sided tape with a strong and weak surface coated with flame-retardant acrylic acid. The micro-porous nano heat insulation sheet is encapsulated in the flame-retardant polyimide thermosetting film in the form of vacuum hot pressing. The double-sided flame-retardant adhesive layer is respectively adhered to both end faces of the flame-retardant polyimide thermosetting film, and the ceramized micro-porous silica foam is arranged on the other end face of the double-sided flame-retardant adhesive layer.

2. The fireproof and heat-insulating pad made of a novel composite material according to claim 1, characterized in that: The ceramized micro-porous silica foam has a density between 350 and 500 kg / m³, a 25% compression resilience in the range of 65 kPa to 120 kPa, a thermal conductivity lower than 0.06 W / (m·K), a bulk flame-retardant rating of V0, and can form a ceramic layer on the surface at high temperatures above 450 °C, and can withstand a maximum of 1000 °C without cracking within 10 minutes.

3. The fireproof and heat-insulating pad made of a novel composite material according to claim 2, characterized in that: The bulk material of the double-sided flame-retardant adhesive layer has a flame-retardant rating of VTM-0. At the same time, the flame-retardant silica gel coated on the double-sided flame-retardant adhesive layer is bonded to the ceramized micro-porous silica foam, and the PET double-sided tape of the double-sided flame-retardant adhesive layer is bonded to the flame-retardant polyimide thermosetting film.

4. The fireproof and heat-insulating pad made of a novel composite material according to claim 3, wherein: The particle size of the nano powder particles used in the micro-porous nano heat insulation sheet is about 30 nm, the overall density is 300 kg / m³ to 450 kg / m³, the thermal conductivity at room temperature is lower than 0.021 W / (m·K), and the thermal conductivity in a high-temperature environment of 800 °C is lower than 0.035 W / (m·K).

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