Flame-retardant heat-conducting multi-element hybrid structural adhesive for new energy lithium battery and preparation method thereof

Abstract

The invention relates to a flame-retardant heat-conducting multi-element hybrid structural adhesive for a new energy lithium battery and a preparation method, and belongs to the technical field of structural adhesives. The flame-retardant heat-conducting multi-component hybrid structural adhesive for the new energy lithium battery comprises a component A and a component B, the component A specifically comprises the following raw materials: modified silane resin, a coupling agent, a filler and epoxy resin, and the component B comprises the following raw materials: an epoxy curing agent, a coupling agent, a filler, a catalyst, hydrophobic fumed silica and a water removal agent. By modifying graphene in the filler, the compatibility with other components is enhanced, so that the multi-component hybrid structural adhesive has high bonding strength, flame retardance and heat-conducting property, also has excellent aging resistance, and can meet the application requirements of the structural adhesive for the power battery module.

Description

Technical Field

[0001] The invention belongs to the technical field of structural adhesives, and relates to a flame-retardant, heat-conductive multi-component hybrid structural adhesive for new energy lithium batteries and a preparation method thereof. Background Art

[0002] With the rapid development of new energy vehicles, the energy density and service life of lithium batteries are increasingly required, which puts more stringent requirements on the performance of structural adhesives. Traditional polyurethane structural adhesives are deficient in thermal conductivity, flame retardancy and long-term aging resistance, and it is difficult to meet the stability requirements of lithium batteries under extreme working conditions (such as high temperature, high humidity, cold and hot shock). In addition, the uneven dispersion of thermal conductive fillers and low flame retardant efficiency in the existing technology limit the comprehensive performance of the colloid. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, the present invention provides a flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries and a preparation method thereof. By modifying the graphene in the filler, the compatibility with other components is enhanced, so that the multi-component hybrid structural adhesive has high bonding strength, flame retardant properties and thermal conductivity, and has excellent aging resistance, which can meet the application requirements of power battery module structural adhesives.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions: A flame-retardant, thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries, the structural adhesive being composed of component A and component B in a mass ratio of 1:1-1.2, wherein component A comprises the following raw materials in parts by weight: 30-35 parts of modified silane resin, 1-2 parts of coupling agent, 20-30 parts of filler, and 10-20 parts of epoxy resin; component B comprises the following raw materials: 10-20 parts of epoxy curing agent, 2-3 parts of coupling agent, 20-30 parts of filler, 1-2 parts of catalyst, 1-3 parts of hydrophobic fumed silica, and 1-2 parts of water scavenger.

[0005] Furthermore, the preparation method of the filler comprises the following steps: (1) Graphene and polyvinyl pyrrolidone are added to anhydrous ethanol, ultrasonically stirred, filtered and vacuum dried to form powder; (2) 3-Isocyanatepropyltrimethoxysilane and powder are placed in ethanol, ultrasonically stirred, and then hydrazine hydrate and ammonia water are added. The mixture is heated and kept warm. After filtration, washing with distilled water, drying and grinding, a black powder is obtained, which is then compounded with boron nitride and magnesium hydroxide to form a filler.

[0006] Furthermore, in the step (1), the mass ratio of graphene, polyvinyl pyrrolidone and anhydrous ethanol is 1-2:10:150-200, the ultrasonic stirring time is 20-30 minutes, and the drying temperature and time are 60-70°C and 48 hours respectively.

[0007] Furthermore, in the step (2), the mass ratio of 3-isocyanatepropyltrimethoxysilane, powder, ethanol, hydrazine hydrate and ammonia water is 1:3-5:10-15:2:3, wherein the mass fraction of ethanol is 75% and the mass fraction of ammonia water is 25%.

[0008] Furthermore, in the step (2), the speed and time of ultrasonic stirring are 150-200 r / min and 2 h respectively, the temperature and time of heating and heat preservation are 95-100° C. and 10-12 h respectively, and the mass ratio of the black powder, boron nitride and magnesium hydroxide is 2-3:2:1.

[0009] Furthermore, the modified silane resin is formed by mixing dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:1.

[0010] The preparation method of the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is as follows: component A is obtained by stirring and mixing raw materials according to parts by weight, and component B is obtained by stirring and mixing raw materials according to parts by weight. After the A component and the B component are evenly mixed, the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is obtained.

[0011] Furthermore, the temperature and time of the stirring and mixing are 45-50° C. and 20-30 min, respectively.

[0012] Beneficial effects of the present invention: By wrapping graphene with polyvinyl pyrrolidone, the dispersion of the filler in the system is enhanced, and then modified with 3-isocyanate propyltrimethoxysilane to further improve the compatibility of graphene. In addition, the flame retardancy and thermal conductivity of the structural adhesive are improved by compounding with boron nitride and magnesium hydroxide. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] The coupling agent involved in the present invention is an epoxy silane coupling agent (KH560), the hydrophobic fumed silica is purchased from Hangzhou Jikang New Materials Co., Ltd., with a CAS number of 7631-86-9, the isocyanate is purchased from Langfang Gaoer Insulation Materials Co., Ltd., the polyvinyl pyrrolidone is purchased from Rongsheng New Materials Technology (Nantong, Jiangsu) Co., Ltd., with a CAS number of 9003-39-8, the dewatering agent is purchased from Dalian Haixin Chemical Co., Ltd., the dimethoxysilane-terminated polyether is purchased from Hubei Maidehao Biotechnology Co., Ltd., the trimethoxysilane-terminated polyether is purchased from Wuhan Huaxiang Kejie Biotechnology Co., Ltd., the epoxy resin is E-51, the epoxy curing agent is polyetheramine D230, and the catalyst is dibutyltin dilaurate.

[0015] Example 1

[0016] A flame-retardant, thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries, the structural adhesive consisting of component A and component B in a mass ratio of 1:1, wherein component A comprises the following raw materials in parts by weight: 30 parts of modified silane resin, 1 part of coupling agent, 20 parts of filler, and 10 parts of epoxy resin; component B comprises the following raw materials: 10 parts of epoxy curing agent, 2 parts of coupling agent, 20 parts of filler, 1 part of catalyst, 1 part of hydrophobic fumed silica, and 1 part of water scavenger.

[0017] The preparation method of the filler comprises the following steps: (1) Graphene and polyvinyl pyrrolidone are added to anhydrous ethanol, ultrasonically stirred, filtered and vacuum dried to form powder; (2) 3-Isocyanatepropyltrimethoxysilane and powder are placed in ethanol, ultrasonically stirred, and then hydrazine hydrate and ammonia water are added. The mixture is heated and kept warm. After filtration, washing with distilled water, drying and grinding, a black powder is obtained, which is then compounded with boron nitride and magnesium hydroxide to form a filler.

[0018] In the step (1), the mass ratio of graphene, polyvinyl pyrrolidone and anhydrous ethanol is 1:10:150, the ultrasonic stirring time is 20 minutes, and the drying temperature and time are 60° C. and 48 hours respectively.

[0019] In the step (2), the mass ratio of 3-isocyanatepropyltrimethoxysilane, powder, ethanol, hydrazine hydrate and ammonia water is 1:3:10:2:3, wherein the mass fraction of ethanol is 75% and the mass fraction of ammonia water is 25%.

[0020] In the step (2), the speed and time of ultrasonic stirring are 150 r / min and 2 h respectively, the temperature and time of heating and heat preservation are 95° C. and 10 h respectively, and the mass ratio of the black powder, boron nitride and magnesium hydroxide is 2:2:1.

[0021] The modified silane resin is prepared by mixing dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:1.

[0022] The preparation method of the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is as follows: component A is obtained by stirring and mixing raw materials according to parts by weight, and component B is obtained by stirring and mixing raw materials according to parts by weight. After the A component and the B component are evenly mixed, the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is obtained.

[0023] The temperature and time of the stirring and mixing are 45° C. and 20 min respectively.

[0024] Example 2

[0025] A flame-retardant, thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries, the structural adhesive consisting of component A and component B in a mass ratio of 1:1.1, wherein component A comprises the following raw materials in parts by weight: 33 parts of modified silane resin, 1.5 parts of coupling agent, 25 parts of filler, and 15 parts of epoxy resin; component B comprises the following raw materials: 15 parts of epoxy curing agent, 2.5 parts of coupling agent, 25 parts of filler, 1.5 parts of catalyst, 2 parts of hydrophobic fumed silica, and 1.5 parts of water scavenger.

[0026] The preparation method of the filler comprises the following steps: (1) Graphene and polyvinyl pyrrolidone are added to anhydrous ethanol, ultrasonically stirred, filtered and vacuum dried to form powder; (2) 3-Isocyanatepropyltrimethoxysilane and powder are placed in ethanol, ultrasonically stirred, and then hydrazine hydrate and ammonia water are added. The mixture is heated and kept warm. After filtration, washing with distilled water, drying and grinding, a black powder is obtained, which is then compounded with boron nitride and magnesium hydroxide to form a filler.

[0027] In the step (1), the mass ratio of graphene, polyvinyl pyrrolidone and anhydrous ethanol is 1.5:10:180, the ultrasonic stirring time is 25 minutes, and the drying temperature and time are 65° C. and 48 hours respectively.

[0028] In the step (2), the mass ratio of 3-isocyanatepropyltrimethoxysilane, powder, ethanol, hydrazine hydrate and ammonia water is 1:4:13:2:3, wherein the mass fraction of ethanol is 75% and the mass fraction of ammonia water is 25%.

[0029] The speed and time of ultrasonic stirring in step (2) are 180 r / min and 2 h respectively, the temperature and time of heating and heat preservation are 98° C. and 11 h respectively, and the mass ratio of the black powder, boron nitride and magnesium hydroxide is 2.5:2:1.

[0030] The modified silane resin is prepared by mixing dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:1.

[0031] The preparation method of the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is as follows: component A is obtained by stirring and mixing raw materials according to parts by weight, and component B is obtained by stirring and mixing raw materials according to parts by weight. After the A component and the B component are evenly mixed, the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is obtained.

[0032] The stirring and mixing temperature and time are 48° C. and 25 min respectively.

[0033] Example 3

[0034] A flame-retardant, thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries, the structural adhesive consisting of component A and component B in a mass ratio of 1:1.2, wherein component A comprises the following raw materials in parts by weight: 35 parts of modified silane resin, 2 parts of coupling agent, 30 parts of filler, and 20 parts of epoxy resin; component B comprises the following raw materials: 20 parts of epoxy curing agent, 3 parts of coupling agent, 30 parts of filler, 2 parts of catalyst, 3 parts of hydrophobic fumed silica, and 2 parts of water scavenger; the modified silane resin is a mixture of dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:1.

[0035] The preparation method of the filler comprises the following steps: (1) Graphene and polyvinyl pyrrolidone are added to anhydrous ethanol, ultrasonically stirred, filtered and vacuum dried to form powder; (2) 3-Isocyanatepropyltrimethoxysilane and powder are placed in ethanol, ultrasonically stirred, and then hydrazine hydrate and ammonia water are added. The mixture is heated and kept warm. After filtration, washing with distilled water, drying and grinding, a black powder is obtained, which is then compounded with boron nitride and magnesium hydroxide to form a filler.

[0036] In the step (1), the mass ratio of graphene, polyvinyl pyrrolidone and anhydrous ethanol is 2:10:200, the ultrasonic stirring time is 30 minutes, and the drying temperature and time are 70° C. and 48 hours respectively.

[0037] In the step (2), the mass ratio of 3-isocyanatepropyltrimethoxysilane, powder, ethanol, hydrazine hydrate and ammonia water is 1:5:15:2:3, wherein the mass fraction of ethanol is 75% and the mass fraction of ammonia water is 25%.

[0038] The speed and time of ultrasonic stirring in step (2) are 200 r / min and 2 h respectively, the temperature and time of heating and heat preservation are 100° C. and 12 h respectively, and the mass ratio of the black powder, boron nitride and magnesium hydroxide is 3:2:1.

[0039] The modified silane resin is prepared by mixing dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:1.

[0040] The preparation method of the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is as follows: component A is obtained by stirring and mixing raw materials according to parts by weight, and component B is obtained by stirring and mixing raw materials according to parts by weight. After the A component and the B component are evenly mixed, the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is obtained.

[0041] The stirring and mixing temperature and time are 50° C. and 30 min respectively.

[0042] Comparative Example 1 On the basis of Example 2, a flame retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is prepared, wherein the structural adhesive is composed of component A and component B in a mass ratio of 1:1.1, wherein component A includes the following raw materials in parts by weight: 33 parts of modified silane resin, 1.5 parts of coupling agent, 25 parts of filler, and 15 parts of epoxy resin; component B includes the following raw materials: 15 parts of epoxy curing agent, 2.5 parts of coupling agent, 25 parts of filler, 1.5 parts of catalyst, 2 parts of hydrophobic fumed silica, and 1.5 parts of water scavenger.

[0043] The preparation method of the filler comprises the following steps: (1) Graphene is added to anhydrous ethanol, ultrasonically stirred, filtered and vacuum dried to form powder; (2) 3-Isocyanatepropyltrimethoxysilane and powder are placed in ethanol, ultrasonically stirred, and then hydrazine hydrate and ammonia water are added. The mixture is heated and kept warm. After filtration, washing with distilled water, drying and grinding, a black powder is obtained, which is then compounded with boron nitride and magnesium hydroxide to form a filler.

[0044] In the step (1), the mass ratio of graphene to anhydrous ethanol is 1.5:10:180, the ultrasonic stirring time is 25 minutes, and the drying temperature and time are 65° C. and 48 hours, respectively.

[0045] In the step (2), the mass ratio of 3-isocyanatepropyltrimethoxysilane, powder, ethanol, hydrazine hydrate and ammonia water is 1:4:13:2:3, wherein the mass fraction of ethanol is 75% and the mass fraction of ammonia water is 25%.

[0046] The speed and time of ultrasonic stirring in step (2) are 180 r / min and 2 h respectively, the temperature and time of heating and heat preservation are 98° C. and 11 h respectively, and the mass ratio of the black powder, boron nitride and magnesium hydroxide is 2.5:2:1.

[0047] The modified silane resin is prepared by mixing dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:1.

[0048] The preparation method of the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is as follows: component A is obtained by stirring and mixing raw materials according to parts by weight, and component B is obtained by stirring and mixing raw materials according to parts by weight. After the A component and the B component are evenly mixed, the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is obtained.

[0049] The stirring and mixing temperature and time are 48° C. and 25 min respectively.

[0050] Comparative Example 2 On the basis of Example 2, a flame retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is prepared, wherein the structural adhesive is composed of component A and component B in a mass ratio of 1:1.1, wherein component A includes the following raw materials in parts by weight: 33 parts of modified silane resin, 1.5 parts of coupling agent, 25 parts of filler, and 15 parts of epoxy resin; component B includes the following raw materials: 15 parts of epoxy curing agent, 2.5 parts of coupling agent, 25 parts of filler, 1.5 parts of catalyst, 2 parts of hydrophobic fumed silica, and 1.5 parts of water scavenger.

[0051] The preparation method of the filler comprises the following steps: (1) Graphene and polyvinyl pyrrolidone are added to anhydrous ethanol, ultrasonically stirred, filtered and vacuum dried to form powder; (2) The powder is then compounded with boron nitride and magnesium hydroxide to form a filler.

[0052] In the step (1), the mass ratio of graphene, polyvinyl pyrrolidone and anhydrous ethanol is 1.5:10:180, the ultrasonic stirring time is 25 minutes, and the drying temperature and time are 65° C. and 48 hours respectively.

[0053] The mass ratio of the powder, boron nitride and magnesium hydroxide is 2.5:2:1.

[0054] The modified silane resin is prepared by mixing dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:1.

[0055] The preparation method of the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is as follows: component A is obtained by stirring and mixing raw materials according to parts by weight, and component B is obtained by stirring and mixing raw materials according to parts by weight. After the A component and the B component are evenly mixed, the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is obtained.

[0056] The stirring and mixing temperature and time are 48° C. and 25 min respectively.

[0057] Comparative Example 3 On the basis of Example 2, the black powder in the filler was removed, and the reduced mass was distributed to the masses of boron nitride and magnesium hydroxide in proportion. Other conditions were consistent with Example 2.

[0058] Comparative Example 4 On the basis of Example 2, the boron nitride in the filler was removed, and the reduced mass was distributed to the masses of the black powder and magnesium hydroxide in proportion. Other conditions were consistent with Example 2.

[0059] Comparative Example 5 On the basis of Example 2, magnesium hydroxide in the filler is removed, and the reduced mass is distributed to the masses of the black powder and boron nitride in proportion. Other conditions are consistent with Example 2.

[0060] Performance Testing The structural adhesives obtained in Examples 1-3 and Comparative Examples 1-5 were used as samples, and the flame retardancy levels were determined according to GB 8410-2006 "Combustion Characteristics of Automotive Interior Materials", and the tests were performed according to the requirements of ASTM D5470-17 Standard Test Method for Thermal Conductivity of Thermally Conductive Insulating Materials. The test results are shown in Table 1.

[0061] Table 1 Performance test results of different structural adhesives Sample Thermal conductivity / W / (m·K) Flame retardant grade UL94 Example 1 2.65 V0 Example 2 2.71 V0 Example 3 2.67 V0 Comparative Example 1 2.34 V0 Comparative Example 2 2.26 V0 Comparative Example 3 1.65 V1 Comparative Example 4 1.75 V0 Comparative Example 5 1.84 V0 It can be seen from Table 1 that the thermal conductivity of Examples 1-3 is much greater than that of Comparative Examples 1-5, among which the thermal conductivity of Comparative Example 3 is the smallest. Except for Comparative Example 3 having a flame retardant grade of V1, the other component grades are all V0; in Comparative Examples 1-2, only the graphene is modified, and its dispersibility and compatibility are weakened; in Comparative Examples 3-5, when any one of the modified graphene, boron nitride, and magnesium hydroxide is removed, its thermal conductivity is greatly reduced, and when the modified graphene is removed, the flame retardancy is also reduced. Therefore, the interaction between the various components is utilized to improve the flame retardancy and thermal conductivity of the flame-retardant and thermally conductive multi-element hybrid structural adhesive for new energy lithium batteries.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. Flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries, characterized in that: The structural adhesive is composed of component A and component B in a mass ratio of 1:1-1.2, wherein component A includes the following raw materials in parts by weight: 30-35 parts of modified silane resin, 1-2 parts of coupling agent, 20-30 parts of filler, and 10-20 parts of epoxy resin; component B includes the following raw materials: 10-20 parts of epoxy curing agent, 2-3 parts of coupling agent, 20-30 parts of filler, 1-2 parts of catalyst, 1-3 parts of hydrophobic fumed silica, and 1-2 parts of water scavenger.

2. The flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries according to claim 1, characterized in that: The preparation method of the filler comprises the following steps: (1) Graphene and polyvinyl pyrrolidone are added to anhydrous ethanol, ultrasonically stirred, filtered and vacuum dried to form powder; (2) 3-Isocyanatepropyltrimethoxysilane and powder are placed in ethanol, ultrasonically stirred, and then hydrazine hydrate and ammonia water are added. The mixture is heated and kept warm. After filtration, washing with distilled water, drying and grinding, a black powder is obtained, which is then compounded with boron nitride and magnesium hydroxide to form a filler.

3. The flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries according to claim 2, characterized in that: In the step (1), the mass ratio of graphene, polyvinyl pyrrolidone and anhydrous ethanol is 1-2:10:150-200, the ultrasonic stirring time is 20-30 minutes, and the drying temperature and time are 60-70°C and 48 hours respectively.

4. The flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries according to claim 2, characterized in that: In the step (2), the mass ratio of 3-isocyanatepropyltrimethoxysilane, powder, ethanol, hydrazine hydrate and ammonia water is 1:3-5:10-15:2:3, wherein the mass fraction of ethanol is 75% and the mass fraction of ammonia water is 25%.

5. The flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries according to claim 2, characterized in that: The speed and time of ultrasonic stirring in step (2) are 150-200 r / min and 2 h respectively, the temperature and time of heating and heat preservation are 95-100° C. and 10-12 h respectively, and the mass ratio of the black powder, boron nitride and magnesium hydroxide is 2-3:2:

1.

6. The flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries according to claim 1, characterized in that: The modified silane resin is prepared by mixing dimethoxysilane-terminated polyether and trimethoxysilane-terminated polyether in a mass ratio of 1:

1.

7. The method for preparing the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries according to claim 1, characterized in that: The preparation method of the structural adhesive is as follows: component A is obtained by stirring and mixing raw materials according to parts by weight, and component B is obtained by stirring and mixing raw materials according to parts by weight, and after the component A and the component B are evenly mixed, a flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries is obtained.

8. The method for preparing the flame-retardant and thermally conductive multi-component hybrid structural adhesive for new energy lithium batteries according to claim 7, characterized in that: The temperature and time of the stirring and mixing are 45-50° C. and 20-30 min respectively.