A heat-insulating treatment liquid, mica board, and preparation method and application thereof

Abstract

The present application relates to the technical field of battery insulation materials, and specifically discloses a heat-insulating treatment liquid, a mica board, and a preparation method and application thereof. The heat-insulating treatment liquid provided in the present application comprises the following components in parts by weight: 40-60 parts of organic silica gel, 35-45 parts of nano-aerogel, 30-40 parts of ceramic powder, and 0.1-0.5 parts of silane coupling agent; the specific surface area of ​​the nano-aerogel is 650-1300 m 2 / g; This application also provides a mica board comprising multiple mica papers and a thermal insulation adhesive layer, with the thermal insulation adhesive layer located between two adjacent mica papers; the thermal insulation adhesive layer is formed by curing a thermal insulation treatment liquid. The mica board provided in this application is not only fireproof and voltage-resistant, but also has excellent thermal insulation properties, meeting the requirements of new energy vehicle power batteries.

Description

Technical Field

[0001] The present application relates to the technical field of battery thermal insulation materials, and in particular to a thermal insulation treatment liquid, a mica board, and a preparation method and application thereof. Background Art

[0002] With the continuous development of new energy vehicles, batteries, as core components, play a major role in new energy vehicles. However, when new energy vehicles are subjected to external impact, excessive charging and discharging, heat accumulation, etc., they can easily cause abnormal temperature rise in the battery, resulting in fire or explosion hazards, posing a potential threat to the safety of the vehicle and its passengers.

[0003] Currently, the primary thermal insulation material used in new energy vehicles on the market is aerogel insulation felt. However, aerogel insulation felts have poor fire resistance and high-temperature electrical resistance, making them unable to meet the increasingly stringent thermal management requirements of new energy vehicle power systems. While existing mica sheets meet the fire resistance and high-temperature electrical resistance requirements, their poor thermal insulation performance makes them inadequate for use in new energy vehicle battery modules, between battery cells, and in components such as battery covers. Therefore, there is an urgent need to develop an insulation material that combines fire resistance, voltage resistance, and thermal insulation properties to meet the requirements for use in new energy vehicle power battery modules, between battery cells, and in components such as battery covers. Summary of the Invention

[0004] In order to obtain a thermal insulation material with fireproof, voltage-resistant and heat-insulating properties, the present application provides a thermal insulation treatment liquid, a mica board, and a preparation method and application thereof.

[0005] In a first aspect, the present application provides a heat-insulating treatment liquid, which adopts the following technical solution:

[0006] A heat-insulating treatment liquid comprises the following components in parts by weight: 40-60 parts of organic silica gel, 35-45 parts of nano aerogel, 30-40 parts of ceramic powder and 0.1-0.5 parts of silane coupling agent.

[0007] This application utilizes organic silica gel, nano-aerogel, ceramic powder, and a silane coupling agent to prepare a thermal insulation treatment fluid. This thermal insulation treatment fluid exhibits excellent bonding and thermal insulation properties. Compared to mica boards made with organic silicone resin adhesives in related art, mica boards made with this thermal insulation treatment fluid are less likely to delaminate at high temperatures and exhibit superior fire resistance, thermal insulation, and voltage resistance.

[0008] In this application, organic silica gel refers to a silicone resin that is heat-resistant to 260°C. Nanoaerogels contain numerous tiny pores, which prevent the free flow of air molecules and, consequently, convection heat transfer, providing excellent insulation. Ceramic powders offer excellent thermal insulation properties, effectively reducing the transfer of temperature between the inside and outside of the mica tape. Silane coupling agents increase the viscosity of the mica paper treatment solution, thereby enhancing the bonding between the mica sheets.

[0009] In the present application, the amount of organic silica gel, nano aerogel, ceramic powder and silane coupling agent added to the thermal insulation treatment liquid will affect the thermal insulation performance of the thermal insulation treatment liquid and the performance of the mica paper obtained. When the amount of organic silica gel added is less than 20 parts, the thermal insulation treatment liquid obtained is too thin, so it cannot form a coating on the surface of the mica paper; when the amount of organic silica gel added is greater than 60 parts, the mica board cracks and delaminates at high temperatures, and the thermal insulation of the obtained mica board is poor. When the amount of nano aerogel added is less than 35 parts, the thermal insulation of the mica board obtained is poor; when the amount of nano aerogel added is greater than 40 parts, the coating formed by the thermal insulation treatment liquid inside the mica board has poor flatness and a large number of pores, the mica board is easy to delaminate at high temperatures, and the thermal insulation is poor. When the amount of ceramic powder added is less than 30 parts, the uniformity of the thermal insulation treatment liquid is poor, and the thermal insulation, insulation and fire resistance of the mica board are not good. When the amount of ceramic powder added exceeds 40 parts per million, an insoluble white solid will form in the insulation treatment liquid, and the resulting mica board will shed powder. Therefore, the present application controls the addition amount of each component of the insulation treatment liquid within the above range to ensure the uniformity and stability of the insulation treatment liquid. The resulting mica paper has excellent fire resistance, voltage resistance, and thermal insulation properties, and does not crack or shed powder.

[0010] Preferably, the specific surface area of ​​the nano aerogel is 650-1300m 2 / g.

[0011] The present application controls the specific surface area of ​​the nano-aerogel within the above range, and the obtained thermal insulation treatment liquid has better comprehensive performance in high-temperature viscosity and thermal insulation.

[0012] In the present application, the nano aerogel may be one or more of silicon aerogel, carbon aerogel, silicon dioxide aerogel and graphene oxide aerogel; preferably, silicon dioxide aerogel.

[0013] Preferably, the ceramic powder is a mixture of 400-700 mesh ceramic powder and 1000-1300 mesh ceramic powder; the weight ratio of the 400-700 mesh ceramic powder to the 1000-1300 mesh ceramic powder is 1:(3.7-6.2).

[0014] Preferably, the weight ratio of the 400-700 mesh ceramic powder to the 1000-1300 mesh ceramic powder is 1:(4.5-5.5).

[0015] In a specific embodiment, the weight ratio of the 400-700 mesh ceramic powder to the 1000-1300 mesh ceramic powder is 1:3.7, 1:4.5, 1:5, 1:5.5 or 1:6.

[0016] In a second aspect, the present application provides a method for preparing a thermal insulation treatment liquid.

[0017] A method for preparing a heat-insulating treatment liquid comprises the following steps: uniformly mixing the components of the heat-insulating treatment liquid, and then stirring the mixture at a rotation speed of 400-1000 r / min for 45-180 min to obtain the heat-insulating treatment liquid.

[0018] In a third aspect, the present application provides a mica board, which adopts the following technical solution:

[0019] A mica board comprises the aforementioned heat-insulating treatment liquid.

[0020] Preferably, the mica board includes a plurality of mica papers and a thermal insulation adhesive layer, wherein the thermal insulation adhesive layer is located between two adjacent mica papers; the thermal insulation adhesive layer is formed by solidifying the thermal insulation treatment liquid.

[0021] In the present application, the thickness of the thermal insulation adhesive layer between two adjacent mica papers is 0.28-0.33 mm, preferably 0.3 mm.

[0022] In the present application, the thickness of the mica board is 2.5-3.5 mm, preferably 3 mm.

[0023] On the fourth side, the present application provides a method for preparing a mica board.

[0024] A method for preparing a mica board comprises the following steps: preparing a heat-insulating treatment liquid, gluing mica paper, compounding mica paper, and hot pressing;

[0025] In the hot pressing step, the hot pressing temperature is 150-250° C., the hot pressing pressure is 2.0-2.6 MPa, and the hot pressing time is 15-30 min.

[0026] Through experimental research, the present application found that in the preparation steps of mica boards: when the hot pressing temperature is lower than 150°C, the adhesion between the mica papers is poor, and the mica boards are prone to delamination; when the hot pressing temperature is higher than 250°C, bubbles will appear in the thermal insulation adhesive layer (formed by solidification of the insulating coating treatment liquid) on the surface of the mica board; when the hot pressing pressure is less than 2.0MPa, the adhesion between the mica papers is poor, and the mica boards are prone to delamination; when the hot pressing pressure is greater than 2.6MPa, the thermal insulation adhesive layer on the surface of the mica board is squeezed and thinned, and the thermal insulation of the mica board is poor. Therefore, the present application controls the extrusion temperature and pressure within the above range, and can obtain mica boards with good adhesion and excellent thermal insulation performance. The mica boards can meet the use requirements of modules between cells of new energy vehicle power battery materials and battery cover plates and other devices.

[0027] Fifthly, the application of the thermal insulation treatment liquid and mica board provided in the present application is used in battery modules and battery cover plates.

[0028] In summary, this application has the following beneficial effects:

[0029] 1. This application utilizes a specific ratio of organic silica gel, nano-aerogel, ceramic powder, and silane coupling agent to prepare a thermal insulation treatment liquid. This thermal insulation treatment liquid is applied to the surface of mica paper using a gluing method. Multiple mica papers are then stacked and extruded to form a mica board. The mica board is resistant to delamination at high temperatures due to the insulating adhesive layer between adjacent mica papers, which improves the adhesion between the mica papers and enhances their thermal insulation properties. Furthermore, the mica board exhibits excellent fire resistance, heat insulation, and voltage resistance.

[0030] 2. In the process of hot pressing the mica paper composite to form the mica board, by controlling the hot pressing pressure to 2.0-2.6MPa and the temperature to 150-250°C, it can be ensured that the mica board after hot pressing does not delaminate and there is no glue overflow, and the thermal insulation performance of the obtained mica board is good.

[0031] 3. This application further selects the surface area of ​​800-1200m 2 / g of nano-aerogel to prepare the heat insulation treatment liquid, the final mica board after burning at 1000℃ temperature is less than 150℃, the normal withstand voltage is 34Mv / mm, and the 1100℃ fire resistance time is more than 1000s.

[0032] 4. This application further selects a mixture of 400-700 mesh and 1000-1300 mesh ceramic powders in a weight ratio of 1: (4.5-5.5) to prepare a heat-insulating treatment liquid. The temperature of the mica board finally obtained after calcination at 1000°C is less than 140°C, the normal withstand voltage is greater than 34Mv / mm, and the refractory time at 1100°C is greater than 1100s. DETAILED DESCRIPTION

[0033] In the first aspect, the present application provides a heat insulation treatment liquid, comprising the following components in parts by weight: 40-60 parts of organic silica gel, 35-45 parts of nano aerogel, 30-40 parts of ceramic powder, and 0.1-0.5 parts of silane coupling agent; the specific surface area of ​​the nano aerogel is 650-1300m 2 / g. Furthermore, the specific surface area of ​​nano aerogel is 800-1200m 2 / g

[0034] Furthermore, the ceramic powder is a mixture of 400-700 mesh ceramic powder and 1000-1300 mesh ceramic powder; the weight ratio of 400-700 mesh ceramic powder to 1000-1300 mesh ceramic powder is 1:(3.7-6.2); further, the weight ratio of 400-700 mesh ceramic powder to 1000-1300 mesh ceramic powder is 1:(4.5-5.5)

[0035] In a second aspect, the present application provides a mica board comprising a plurality of mica papers and a thermal insulation adhesive layer, wherein the thermal insulation adhesive layer is located between two adjacent mica papers; the thermal insulation adhesive layer is formed by solidifying the thermal insulation treatment liquid.

[0036] The method for preparing the mica plate comprises the following steps:

[0037] (1) Preparation of thermal insulation treatment liquid: uniformly mix the components of the thermal insulation treatment liquid, and then stir at a speed of 400-1000 r / min for 45-180 min to obtain the thermal insulation treatment liquid.

[0038] (2) Gluing mica paper: The heat-insulating treatment liquid is placed in a glue tank. A transfer roller is installed above the glue tank. The mica paper passes over the transfer roller. By rotating the transfer roller, the heat-insulating treatment liquid is transferred to the surface of the mica paper.

[0039] (3) Composite mica paper: The glued mica paper is laminated.

[0040] (4) hot pressing; hot pressing the composite mica paper to obtain a mica board; the hot pressing temperature is 150-250°C, the hot pressing pressure is 2.0-2.6MPa, and the hot pressing time is 15-30min.

[0041] In this application, the mica paper model is P506, purchased from Pingjiang County Weipai Mica Insulation Material Co., Ltd.; the organic silica gel is a silicone resin purchased from Hubei Xinsihai Chemical Co., Ltd.; the nano aerogel is a silica aerogel purchased from Shanghai Kaiyin Chemical Co., Ltd.; the ceramic powder is aluminum nitride, model AIN-H, purchased from Liaoning Desheng Special Ceramics Manufacturing Co., Ltd.; and the silane coupling agent is KH550, purchased from Nanjing Pinning Coupling Agent Co., Ltd. All other reagents and solvents are commercially available.

[0042] The present application is further described in detail below with reference to embodiments and performance testing.

[0043] Examples 1-7

[0044] Examples 1-7 provide a mica board respectively. The difference lies in the amount of each component of the heat insulation treatment liquid used in the mica board, as shown in Table 1.

[0045] The preparation method of the above mica plate is as follows:

[0046] (1) Preparation of thermal insulation treatment liquid: uniformly mix the components of the thermal insulation treatment liquid, and then stir at a speed of 400-1000 r / min for 45-180 min to obtain the thermal insulation treatment liquid.

[0047] (2) Gluing mica paper: The heat-insulating treatment liquid is placed in a glue tank. A transfer roller is installed above the glue tank. The mica paper passes over the transfer roller. By rotating the transfer roller, the heat-insulating treatment liquid is transferred to the surface of the mica paper.

[0048] (3) Composite mica paper: The glued mica paper is laminated.

[0049] (4) Hot pressing: Hot pressing the composite mica paper to obtain a mica board at a temperature of 150-250°C, a pressure of 2.0-2.6 MPa, and a time of 15-30 minutes. The mica board has a thickness of 3 mm, and the thickness of the thermal insulation adhesive layer formed by the thermal insulation treatment liquid in the mica board is 0.3 mm.

[0050] Table 1 Amount of each component of the heat insulation treatment solution in Examples 1-7

[0051]

[0052] Examples 8-10

[0053] Examples 8-10 were carried out according to the method of Example 2, except that the specific surface area of ​​the nanoaerogel is shown in Table 2.

[0054] Table 2 Specific surface area of ​​nano aerogels used in Example 2 and Examples 8-10

[0055]

[0056] Examples 11-16

[0057] Examples 11-16 were carried out according to the method of Example 2, except that the components and proportions of the ceramic powder were as shown in Table 3. In Examples 11-16, the amount of ceramic powder used was 35 g.

[0058] Table 3 Ceramic powder used in Example 2 and Examples 11-16

[0059]

[0060]

[0061] Example 17

[0062] Example 17 was carried out according to the method of Example 2, except that the hot pressing temperature in the hot pressing forming step was 150°C.

[0063] Example 18

[0064] Example 18 was carried out according to the method of Example 2, except that the hot pressing temperature in the hot pressing forming step was 250°C.

[0065] Example 19

[0066] Example 19 was carried out according to the method of Example 2, except that the hot pressing pressure in the hot pressing molding step was 2.6 MPa.

[0067] Example 20

[0068] Example 20 was carried out according to the method of Example 2, except that the hot pressing pressure in the hot pressing molding step was 2.0 MPa.

[0069] Comparative Examples 1-7

[0070] Comparative Examples 1-7 each provide a mica board.

[0071] Comparative Examples 1-7 were carried out according to the method of Example 2, except that: the heat insulation treatment liquid in the mica boards of Comparative Examples 1-7 was specifically shown in Table 4 below.

[0072] Table 4 Amount of each component of the heat insulation treatment liquid in the mica board provided by Comparative Examples 1-7

[0073]

[0074] Comparative Example 8

[0075] Comparative Example 8 was carried out according to the method of Example 2, except that the components and amounts of the heat insulation treatment liquid were: 50 g of silicone resin, 35 g of nano-aluminum nitride, 35 g of ceramic powder, and 0.3 g of silane coupling agent.

[0076] Comparative Example 9

[0077] Comparative Example 9 was carried out according to the method of Example 2, except that the hot pressing temperature in the hot pressing forming step was 270°C.

[0078] Comparative Example 10

[0079] Comparative Example 10 was carried out according to the method of Example 2, except that the hot pressing pressure in the hot pressing forming step was 2.8 MPa.

[0080] Performance testing

[0081] The physical properties and performance of the mica boards obtained in Examples 1-20 and Comparative Examples 1-10 of the present application were tested, and the results are shown in Table 5.

[0082] 1. Surface Properties: Observe the mica board surface for smoothness, powder shedding, and cracks in the coating. Note: If the surface properties of the mica paper or mica board are poor, thermal insulation and voltage withstand tests will be discontinued, indicated by a " / " in Table 7.

[0083] 2. Thermal insulation performance test: Use a 1000℃ flame to burn one side of the mica board for 10 minutes, and then test the temperature of the other side of the mica board.

[0084] 3. Normal withstand voltage: Use a withstand voltage tester to perform a pressure test on the mica board under normal conditions. For specific methods, please refer to GB / T5019.2-2009 "Mica-based insulating materials" Part 2: Test methods.

[0085] 4. Fire resistance: Test the fire resistance time of mica board at 1100℃.

[0086] 5. High temperature bonding performance:

[0087] (1) Place the mica plate in a high temperature of 750℃ for 10 minutes, take it out, and use a stripping machine to peel off the mica to observe whether it falls off in pieces or blocks.

[0088] (2) Fix the mica board on the test frame and burn it with a 750℃ flame for 10 minutes. Then use a stripping machine to peel off the mica and observe whether it falls off in pieces or chunks.

[0089] Table 5 Mica tape performance test results of Examples 1-20 and Comparative Examples 1-10

[0090]

[0091]

[0092]

[0093] According to the test results in Table 5, the mica boards provided in Examples 1-20 of the present application have a smooth surface, no powder loss, and no cracks. When one side of the mica board is burned at 1000°C for 10 minutes, the surface temperature of the other side is ≤160°C, indicating that the mica board has excellent thermal insulation performance. In addition, the above-mentioned mica board has a withstand voltage of 29-40kV / mm under normal conditions and a fire resistance time of >900s at 1000°C, indicating that the above-mentioned mica board has excellent insulation and fire resistance. Therefore, the mica board provided in this application has fire resistance, voltage resistance, and thermal insulation performance, and has good surface performance and no delamination at high temperatures. It can fully meet the use requirements of new energy vehicle power battery materials between module cells and battery cover materials and other device materials.

[0094] In Comparative Example 1, since the content of the organic silicone resin in the heat-insulating treatment liquid is relatively low, the heat-insulating treatment liquid cannot form a coating between the mica plates.

[0095] In Comparative Example 2, due to the high content of organic silicone resin in the heat-insulating treatment liquid, the mica board cracked, peeled off at high temperature, and fell off in chunks.

[0096] Although the mica board obtained in Comparative Example 3 has a smooth surface, no powdering, and no cracks, the thermal insulation performance of the mica board is poor due to the low content of nano aerogel in the thermal insulation treatment liquid.

[0097] In Comparative Example 4, due to the high content of nano-aerogel in the thermal insulation treatment liquid, the coating formed on the surface between the mica papers by the thermal insulation treatment liquid has poor flatness and a large number of pores. Therefore, the thermal insulation performance of the obtained mica board is poor, and the mica board peels off at high temperature and flaks off.

[0098] In Comparative Example 5, since the content of ceramic powder in the thermal insulation treatment liquid is too low, the uniformity of the thermal insulation treatment liquid is poor, and the mica board prepared using the thermal insulation, insulation and fire resistance are not good.

[0099] In Comparative Example 6, since the content of ceramic powder in the heat-insulating treatment liquid was too high, an insoluble white solidified substance appeared in the heat-insulating treatment liquid, and the mica board finally obtained showed powdering.

[0100] In Comparative Example 7, since no silane coupling agent was added to the heat-insulating treatment liquid, the viscosity of the heat-insulating treatment liquid was poor, and the mica board finally obtained peeled off at high temperature and fell off in chunks.

[0101] The mica plate obtained in Comparative Example 8 peeled off at a high temperature of 1000° C., and there was block-like shedding.

[0102] There are a large number of bubbles in the thermal insulation layer in the middle of the mica board obtained in Comparative Example 9, and the thermal insulation, electrical insulation and fire resistance of the mica board are all relatively low.

[0103] Comparative Example 10: The hot pressing pressure is too high, which causes the mica board to become thinner, and the thermal insulation, electrical insulation and fire resistance of the mica board are all poor.

[0104] The test results of Example 2 and Examples 8-10 show that the temperature of the mica board obtained in Example 8 after being burned at 1000℃ is 168℃, the normal withstand voltage is 31Mv / mm, and the fire resistance time at 1100℃ is 867s. The temperature of the mica board obtained in Example 10 after being burned at 1000℃ is 157℃, the normal withstand voltage is 32Mv / mm, and the fire resistance time at 1100℃ is 965s; while the temperature of the mica board obtained in Example 2 and Example 9 after being burned at 1000℃ is less than 150℃, the normal withstand voltage is 34Mv / mm, and the fire resistance time at 1100℃ is greater than 1000s. Therefore, it is shown that the specific surface area of ​​the nano aerogel is further controlled within the range of 800-1200m 2 / g, a mica board with better comprehensive performance in heat insulation, insulation and fire resistance can be obtained.

[0105] The test results of Examples 2 and 11-16 show that the ceramic powder of the insulation treatment liquid of Examples 12-16 is further selected as a mixture of 400-700 mesh and 1000-1300 mesh. The thermal insulation and insulation performance of the mica boards obtained are significantly improved, and the fire resistance performance is also slightly improved. Further comparison shows that the temperature of the mica boards obtained in Examples 13-15 after calcination at 1000°C is less than 140°C, the normal withstand voltage is greater than 34Mv / mm, and the fire resistance time at 1100°C is greater than 1100s. This shows that by controlling the weight ratio of the 400-700 mesh to 1000-1300 mesh ceramic powder within the range of 1: (4.5-5.5), the mica boards obtained in this application have better comprehensive performance in thermal insulation, insulation, and fire resistance.

[0106] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A mica board, characterized in that: The mica board includes a plurality of mica papers and a heat-insulating adhesive layer, wherein the heat-insulating adhesive layer is located between two adjacent mica papers; the heat-insulating adhesive layer is formed by solidifying a heat-insulating treatment liquid; The heat insulation treatment liquid comprises the following components in parts by weight: 50 parts of organic silica gel, 40 parts of nano aerogel, 35 parts of ceramic powder and 0.3 parts of silane coupling agent; The specific surface area of ​​the nano aerogel is 800-1000m 2 / g; The ceramic powder is a mixture of 400-700 mesh ceramic powder and 1000-1300 mesh ceramic powder; the weight ratio of the 400-700 mesh ceramic powder to the 1000-1300 mesh ceramic powder is 1:(4.5-5.5).

2. The mica board according to claim 1, characterized in that The thickness of the mica plate is 2.5-3.5 mm.

3. The method for preparing a mica board according to any one of claims 1 to 2, characterized in that: The following steps are involved: Preparation of heat insulation treatment liquid, mica paper gluing, mica paper compounding, hot pressing molding; In the hot pressing step, the hot pressing temperature is 150-250° C., the hot pressing pressure is 2.0-2.6 MPa, and the hot pressing time is 15-30 min.

4. Use of the mica board according to any one of claims 1 to 2 in a battery module or a battery cover.

Images