A fire-resistant ceramic fiberboard

Abstract

The application relates to the technical field of fireproof protection materials for new energy automobile battery modules, and discloses a fireproof ceramic fiber plate which comprises the following raw materials: 2000-3000 parts by weight of water, 30-50 parts by weight of ceramic fiber, 2-5 parts by weight of silicon dioxide powder, 3-10 parts by weight of porcelain-forming filler, 5-15 parts by weight of glass powder, 20-40 parts by weight of modified silicon sol and 0.5-1 part by weight of flocculating agent; the modified silicon sol is prepared by modifying silicon sol by using coupling agent a or coupling agent b. The application develops a fireproof ceramic fiber plate which is not burnt through and has no surface cracks after being subjected to 1500 DEG C flame front burning for 30 minutes, and exhibits excellent fireproof performance. The fireproof ceramic fiber plate can be used as the fireproof protection material between new energy automobile battery modules, and can block flame impact and prevent battery thermal runaway spreading.

Description

Technical Field

[0001] This invention relates to the field of fire-resistant protective materials for new energy vehicle battery modules, specifically a fire-resistant ceramic fiber board. Background Technology

[0002] Ceramic fiberboard is a high-strength, impact-resistant, and heat-insulating refractory material with a certain supporting function, which can be used as a fireproof material between battery modules in new energy vehicles. In the event of thermal runaway due to overcharging, overheating, short circuits, collisions, or compression, ceramic fiberboard can effectively block flame impacts and absorb the enormous energy generated during the thermal runaway explosion, thereby preventing the spread of battery thermal runaway and ensuring the safety of users' lives and property.

[0003] Currently, silica sol is commonly used as a binder for ceramic fiberboard. Although ceramic fiberboard made from conventional inorganic silica sol has high hardness, it is brittle and prone to cracking. Furthermore, during actual firing, the silica sol is easily decomposed at high temperatures due to the generation of small molecule byproduct water, which can lead to the ceramic fiberboard being burned through. Summary of the Invention

[0004] This invention independently developed a refractory ceramic fiber board, which can be used as a refractory protective material between battery modules of new energy vehicles, playing a role in blocking flame impact and preventing the spread of battery thermal runaway.

[0005] A refractory ceramic fiber board, comprising the following raw materials:

[0006] 2000-3000 parts by weight of water;

[0007] 30-50 parts by weight of ceramic fiber;

[0008] 2-5 parts by weight of silica powder;

[0009] 3-10 parts by weight of ceramic filler;

[0010] 5-15 parts by weight of glass powder;

[0011] 20-40 parts by weight of modified silica sol;

[0012] 0.5-1 parts by weight of flocculant;

[0013] The preparation method of the modified silica sol is as follows: the silica sol is modified by coupling agent a or coupling agent b, and the silanol or zirconium hydroxyl functional groups obtained by the hydrolysis reaction of the coupling agent undergo a dehydration condensation reaction with the hydroxyl functional groups contained in the silica sol.

[0014] The mass ratio of coupling agent to silica sol in modified silica sol is 1:(5-15).

[0015] Preferably, the coupling agent a is prepared by: reacting the Si-H functional groups of ethyleneoxytrimethylsilane and dimethylethoxysilane by an addition reaction, and controlling the molar ratio of ethyleneoxytrimethylsilane and dimethylethoxysilane participating in the reaction to be (1.01-1.09):1, thereby generating coupling agent a.

[0016] Preferably, the coupling agent b is prepared by:

[0017] Intermediate 1 is generated by the addition reaction of ethyleneoxytrimethylsilane with the Si-H functional groups of dimethylsilyl POSS, and the molar ratio of ethyleneoxytrimethylsilane to dimethylsilyl POSS participating in the reaction is controlled to be (8.01-8.09):1.

[0018] Intermediate 2 was synthesized from intermediate 1 using trifluoromethanesulfonic acid as the opening reagent via the vertex-opening method.

[0019] Using intermediate 2 as a raw material and tetrabutyl zirconate as a capping agent, coupling agent b was synthesized via the vertex-capping method.

[0020] Preferably, the ceramic fiber is one or a combination of more than one of aluminosilicate fiber, alumina fiber, mullite fiber, quartz fiber, silicon carbide fiber, zirconium oxide fiber and nitride fiber.

[0021] Preferably, the ceramic filler is one or a combination of one or more of wollastonite, diatomite, kaolin, calcium carbonate, and mica powder.

[0022] Preferably, the flocculant is one or a combination of more than one of polyacrylamide, polyethyleneimine, aluminum sulfate, ferric sulfate and polyaluminum chloride.

[0023] Preferably, the refractory ceramic fiberboard has a tensile strength of (12-17) MPa and does not burn through when burned at 1500°C for 30 minutes.

[0024] Beneficial effects:

[0025] This invention designs and synthesizes coupling agent a and coupling agent b, and uses coupling agent a or coupling agent b to modify silica sol to prepare modified silica sol;

[0026] A refractory ceramic fiber board was prepared using aluminosilicate fiber as the ceramic fiber raw material, silica powder as the stability enhancer, mica powder and calcium carbonate as ceramic fillers, glass powder as the hardness enhancer, modified silica sol as the binder, and polyacrylamide as the flocculant. On the one hand, the glass powder in the ceramic fiber board melts upon heating and works together with silica powder and ceramic fillers to form a dense ceramic layer, achieving the technical effect that the ceramic fiber board does not crack after being fired at 1500℃ for 30 minutes. On the other hand, the coupling agent in the modified silica sol provides a flexible surface layer for the silica sol, allowing the stress between the silica sol surfaces to be uniformly transmitted, thereby enhancing the strength and toughness of the silica sol material. This results in a significant improvement in the tensile strength, refractory performance, and refractory stability of the ceramic fiber board. Detailed Implementation

[0027] Example 1:

[0028] A refractory ceramic fiber board, the raw material formula of which is shown in Table 1;

[0029] Table 1 Raw material formulation for refractory ceramic fiberboard

[0030]

[0031]

[0032] The modified silica sol in Table 1 is prepared by modifying the silica sol with self-made coupling agent a or coupling agent b, and then reacting the silanol or zirconol functional groups obtained by the hydrolysis reaction of the coupling agent with the hydroxyl functional groups contained in the silica sol (purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd.) through a dehydration condensation reaction.

[0033] In the modified silica sol, the mass ratio of coupling agent to silica sol is 1:10.

[0034] The chemical structure and preparation method of coupling agent a are described in Experimental Example 1; the chemical structure and preparation method of coupling agent b are described in Experimental Example 2.

[0035] Example 2:

[0036] A method for preparing a refractory ceramic fiber board includes the following steps:

[0037] Step 1, Preparation of modified silica sol: Add 40g of silica sol to 80mL of anhydrous ethanol, stir and mix at room temperature for 10min, then add 4g of coupling agent, stir and react at room temperature for 10min, then add 20mL of water, adjust the pH of the solution to 4.5 with concentrated hydrochloric acid, stir and mix at room temperature for 10min, then heat to 40℃ and stir and react for 2h, let stand for 24h to obtain modified silica sol;

[0038] Step 2, Preparation of ceramic mixed solution: Add 40g of aluminosilicate fiber to 2500mL of water and stir and disperse at 2000rpm for 30min using a high-speed stirrer. Then add 3g of silica powder, 2g of mica powder, 3g of calcium carbonate and 10g of glass powder in sequence, and stir and disperse at 2000rpm for 15min to obtain ceramic mixed solution.

[0039] Step 3, prepare ceramic slurry: Add 30g of the modified silica sol prepared in Step 1 to the ceramic slurry prepared in Step 2, stir and disperse at 1000rpm for 30min using a high-speed mixer, and finally add 0.8g of polyacrylamide to obtain ceramic slurry;

[0040] Step 4, Preparation of refractory ceramic fiber board: Pour the ceramic slurry prepared in step 3 into a mold, dehydrate and shape it, and hot press and dry it (hot pressing pressure 5.5MPa, drying temperature 150℃, time 10min) to obtain refractory ceramic fiber board;

[0041] When the coupling agent is coupling agent a, the product prepared is denoted as refractory ceramic fiber board I;

[0042] When the coupling agent is coupling agent b, the prepared product is denoted as refractory ceramic fiber board II.

[0043] Performance testing:

[0044] (1) Tensile strength test: The tensile strength of the sample was tested according to GB / T 17911-2018 standard;

[0045] (2) Fire resistance test: keep the front of the sample burning at 1500℃ for 30 minutes and observe whether the sample is burned through;

[0046] (3) Fire resistance stability test: The sample is burned with a 1000℃ flame for 20 seconds, followed by a 1MPa gas impact on the front of the sample for 5 seconds. This is one cycle. Observe whether the sample is burned through after 20 cycles.

[0047] The results of the above performance experiments are shown in Table 2;

[0048] Table 2. Experimental results of the performance of refractory ceramic fiberboard

[0049]

[0050] Note: The only difference between the comparative example and the refractory ceramic fiber board is that silica sol is used instead of modified silica sol.

[0051] Based on the performance test results in Table 2, the following conclusions were drawn:

[0052] Conclusion 1: The refractory ceramic fiberboard product developed in this invention does not burn through after being subjected to a flame at 1500℃ for 30 minutes, and the surface is free of cracks, demonstrating excellent fire resistance.

[0053] Conclusion 2: Compared with ceramic fiber boards using conventional silica sol, the ceramic fiber boards prepared by modifying silica sol with self-made coupling agent a or coupling agent b in this invention have achieved significant improvements in tensile strength, fire resistance and fire stability.

[0054] Experimental Example 1:

[0055] Preparation of coupling agent a: Coupling agent a is generated by the addition reaction of the Si-H functional groups of ethyleneoxytrimethylsilane and dimethylethoxysilane, with the molar ratio of ethyleneoxytrimethylsilane to dimethylethoxysilane controlled at 1.05:1. Its chemical structure is as follows:

[0056]

[0057] The specific experimental steps for preparing coupling agent a are as follows: Under nitrogen protection, 1.0 g of dimethylethoxysilane and 20 mL of anhydrous tetrahydrofuran were added to a three-necked flask and stirred at room temperature until completely dissolved. Then, 1.5 mL of ethyleneoxytrimethylsilane and 2 drops of caster catalyst were added dropwise to the three-necked flask. The mixture was heated to 70 °C and stirred under reflux for 8 h. After cooling to room temperature, the solvent was removed by rotary evaporation and the mixture was dried under vacuum to obtain coupling agent a.

[0058] The proton NMR spectrum of coupling agent a is characterized as follows: 1 H NMR (CDCl3, 400MHz) δ: 0.08 (s, 6H), 0.14 (s, 9H), 0.90-0.94 (t, 2H), 1.08-1.12 (t, 3H), 3.57-3.61 (t, 2H), 3.67-3.73 (m, 2H).

[0059] Experimental Example 2:

[0060] The preparation steps for coupling agent b are as follows:

[0061] Step 1: An addition reaction is carried out between ethyleneoxytrimethylsilane and the Si-H functional groups of dimethylsilyl POSS, with the molar ratio of ethyleneoxytrimethylsilane to dimethylsilyl POSS controlled at 8.08:1, to generate intermediate 1, whose chemical structural formula is as follows:

[0062]

[0063] Step 2: Using intermediate 1 as a raw material and trifluoromethanesulfonic acid as an opening reagent, intermediate 2 is synthesized via the vertex-opening method. Its chemical structural formula is as follows:

[0064]

[0065] Step 3: Using intermediate 2 as a raw material and tetrabutyl zirconate as a capping agent, coupling agent b is synthesized via the vertex-capping method. Its chemical structural formula is as follows:

[0066]

[0067] The specific experimental steps for preparing coupling agent b are as follows:

[0068] Under nitrogen protection, 5.1 g of dimethylsilyl POSS and 50 mL of anhydrous tetrahydrofuran were added to a three-necked flask and stirred at room temperature until completely dissolved. Then, 6.0 mL of ethyleneoxytrimethylsilane and 5 drops of castor catalyst were added dropwise to the three-necked flask. The mixture was heated to 70 °C and refluxed for 12 h. After cooling to room temperature, the solvent was removed by rotary evaporation and the mixture was dried under vacuum to obtain intermediate 1.

[0069] 6.4 g of intermediate 1 and 80 mL of anhydrous tetrahydrofuran were added to a three-necked flask and stirred at room temperature until completely dissolved. Then, 7.5 g of trifluoromethanesulfonic acid was added to the three-necked flask and stirred at room temperature for 0.5 h. After the reaction was completed, the mixture was filtered, and 5A molecular sieve was added to absorb and remove residual trifluoromethanesulfonic acid. The solvent was removed by rotary evaporation and vacuum drying to obtain intermediate 2.

[0070] Under nitrogen protection, 4.3 g of intermediate 2 and 50 mL of anhydrous tetrahydrofuran were added to a three-necked flask and stirred at room temperature until completely dissolved. Then, the flask was placed in an ice-water bath, and 1.0 mL of tetrabutyl zirconate was added dropwise. The mixture was stirred in the ice-water bath for 30 min, then the ice-water bath was removed, and the mixture was stirred at room temperature for another 6 h. The solvent was removed by rotary evaporation, and the solution was concentrated to a saturated state. The solution was then settled by acetonitrile, filtered, washed, and dried under vacuum to obtain coupling agent b.

[0071] The proton NMR spectrum of coupling agent b is characterized as follows: 1 H NMR (CDCl3, 400MHz) δ: 0.06 (s, 42H), 0.12 (s, 63H), 0.85-0.89 (t, 3H), 0.97-1.00 (t , 14H), 1.39-1.49(m, 2H), 1.67-1.74(m, 2H), 3.60-3.63(t, 14H), 3.75-3.78(t, 2H).

Claims

1. A fire resistant ceramic fiberboard, characterized by, The raw materials include: 2000-3000 parts by weight of water; 30-50 parts by weight of ceramic fiber; 2-5 parts by weight of silica powder; 3-10 parts by weight of porcelain-forming filler; 5-15 parts by weight of glass powder; 20-40 parts by weight of modified silica sol; 0.5-1 part by weight of flocculating agent; The preparation method of the modified silica sol is as follows: the silica sol is modified by using a coupling agent b, and the silicon hydroxyl or zirconium hydroxyl functional groups obtained by the hydrolysis reaction of the coupling agent b are subjected to dehydration condensation reaction with the hydroxyl functional groups contained in the silica sol to obtain the modified silica sol; The mass ratio of the coupling agent b to the silica sol in the modified silica sol is 1:(5-15); The chemical structural formula of the coupling agent b is as follows: 。 2. A fire resistant ceramic fiberboard according to claim 1, wherein, The preparation method of the coupling agent b is as follows: An intermediate 1 is generated by the addition reaction of ethenoxyl trimethylsilane and the Si-H functional groups of dimethylsilyl-POSS, and the molar ratio of ethenoxyl trimethylsilane and dimethylsilyl-POSS participating in the reaction is controlled to be (8.01-8.09):1; The intermediate 2 is synthesized by the vertex-opening method using the intermediate 1 as the raw material and trifluoromethanesulfonic acid as the opening reagent; The coupling agent b is synthesized by the vertex-capping method using the intermediate 2 as the raw material and tetrabutyl zirconate as the capping reagent.

3. A fire resistant ceramic fiberboard according to claim 1, wherein, The ceramic fiber is one or a combination of one or more of aluminum silicate fiber, aluminum oxide fiber, mullite fiber, quartz fiber, silicon carbide fiber, zirconium oxide fiber and nitride fiber.

4. A fire resistant ceramic fiberboard according to claim 1, wherein, The porcelain-forming filler is one or a combination of one or more of wollastonite, diatomite, kaolin, calcium carbonate and mica powder.

5. A fire resistant ceramic fiberboard according to claim 1, wherein The flocculating agent is one or a combination of one or more of polyacrylamide, polyethyleneimine, aluminum sulfate, iron sulfate and polyaluminum chloride.

6. A fire resistant ceramic fiberboard according to any one of claims 1-5, characterized in that, The tensile strength of the refractory ceramic fiber board is (12-17) MPa, and the board is not burned through when burned at a temperature of 1500 DEG C for 30 min.

7. Use of a fire resistant ceramic fibre board according to any one of claims 1-5, characterised in that The refractory ceramic fiber board serves as a refractory protection material between battery modules of a new energy vehicle, and plays a role in blocking flame impact and preventing the spread of battery thermal runaway.

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