High-stability hydrogen energy fuel cell frame material and preparation method thereof

Abstract

The invention discloses a high-stability hydrogen energy fuel cell frame material and a preparation method thereof, and belongs to the technical field of cell material processing. The high-stability hydrogen energy fuel cell frame material is used for solving the technical problem that the high temperature resistance and low temperature resistance of a cell frame material in the prior art need to be further improved. Comprising the following components in parts by weight: 40-60 parts of epoxy resin, 10-20 parts of phthalic dimethyl resin, 15-25 parts of a modified curing agent, 5-10 parts of a modified capsule and 8-10 parts of an auxiliary additive. The heat-conducting composite liquid with good heat-conducting property is prepared, and the modified capsule with the phase change function is prepared from the heat-conducting composite liquid through an emulsion polymerization method, so that the high-temperature resistance and low-temperature resistance of the battery frame material are improved, and the mechanical strength of the battery frame material is also improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery material processing, in particular to a high-stability hydrogen energy fuel cell frame material and a preparation method thereof. BACKGROUND

[0002] With the wide application of hydrogen energy fuel cells in the fields of new energy vehicles, distributed power generation and portable energy, higher requirements are put forward for the performance of structural components of the hydrogen energy fuel cells, especially the frame materials in fuel cell modules. The frame materials need not only to have excellent mechanical strength to bear the stacking pressure, but also to have good thermal conductivity, dimensional stability and durability under high and low temperature environments. At present, the commonly used frame materials are mainly thermosetting resins, including epoxy resins, o-benzene dimethyl resins and polyimide resins. In order to further meet the composite performance requirements of the frame on thermal conductivity, impact resistance and thermal fatigue resistance, researchers usually adopt the ways of filler enhancement, interface modification, microcapsule coating, structure blending and curing agent structure optimization to improve the performance of the matrix materials, so as to cope with various performance challenges under complex service environments.

[0003] In the prior art, epoxy resins and o-benzene dimethyl resins have good mechanical properties and heat resistance, but they still have certain performance bottlenecks, which limit their long-term use stability in high-power, high-frequency cold and hot cycle fuel cell systems. On the one hand, the thermal conductivity of the curing system of the traditional epoxy or o-benzene dimethyl resin is low, which leads to the difficulty in timely release of local heat under high heat conditions, and easily causes thermal stress concentration, uneven material expansion, and then induces the problems of frame warping and cracking, on the other hand, due to the high rigidity of the curing network structure of the epoxy resin and the o-benzene dimethyl resin but the lack of flexible chain segments, the thermal stress buffering capacity is poor, which leads to the generation of microcracks or interface delamination under the condition of high and low temperature repeated cycles, and shows poor high and low temperature resistance and mechanical strength. At the same time, in order to improve the performance of the resin, the heat-resistant and toughening fillers added in the preparation process aggravate the local stress concentration and performance attenuation in the process of force-heat coupling due to poor dispersibility and poor interface compatibility.

[0004] In view of the technical defects in this aspect, a solution is proposed. SUMMARY

[0005] The application aims to provide a high-stability hydrogen energy fuel cell frame material and a preparation method thereof, which are used to solve the technical problem that the high temperature resistance and low temperature resistance of the battery frame material in the prior art need to be further improved.

[0006] The purpose of the application can be achieved by the following technical solutions:

[0007] A high-stability hydrogen energy fuel cell frame material, comprising the following components by weight parts: 40-60 parts of epoxy resin, 10-20 parts of o-xylylene resin, 15-25 parts of modified curing agent, 5-10 parts of modified capsule and 8-10 parts of auxiliary additive;

[0008] The auxiliary additive is composed of plasticizer, antioxidant, flame retardant and lubricant in a mass ratio of 3:1:5:0.5.

[0009] Further, the modified curing agent is prepared by the following steps:

[0010] A1, 4, 4-bis (4-hydroxyphenyl) valeric acid, N, N-dicyclohexyl carbodiimide, 4-dimethylamino pyridine p-toluene sulfonate and N, N-dimethylformamide are placed in a reaction kettle and stirred, and the reaction is carried out at room temperature for 20-24h, and the modified curing agent precursor is obtained after treatment.

[0011] A2, polyformaldehyde, 2-furfurylamine and N, N-dimethylformamide are placed in a reaction kettle and stirred for 10-15min, then the modified curing agent precursor is added, the reaction kettle is heated to 85-95℃, and the reaction is carried out for 6-8h, and the modified curing agent is obtained after treatment.

[0012] The preparation reaction formula of the modified curing agent is:

[0013]

[0014] The preparation reaction principle of the modified curing agent is:

[0015] During the reaction, under the catalysis of N, N-dicyclohexyl carbodiimide and 4-dimethylamino pyridine p-toluene sulfonate, the carboxyl group and the hydroxyl group in the 4, 4-bis (4-hydroxyphenyl) valeric acid molecule occur esterification reaction, forming branched modified curing agent precursor, further, furfurylamine and polyformaldehyde form imine type intermediate at high temperature, and the nucleophilic reaction occurs with the phenolic hydroxyl group in the modified curing agent precursor, and the benzoxazine ring structure is generated through the ring closing process, and the modified curing agent is obtained.

[0016] Further, in step A1, the use amount ratio of the 4,4-bis(4-hydroxyphenyl)valeric acid, N,N-dicyclohexyl carbodiimide, 4-dimethylamino pyridine p-toluenesulfonate and N,N-dimethylformamide is 4-6 g:1-3 g:1-2 g:80-120 mL, and the post-treatment step includes: after the reaction is completed, the reaction system is cooled to room temperature, and then filtered, and the filtrate is transferred to a rotary evaporator with a temperature of 90-100 DEG C, and rotary evaporation is performed under reduced pressure until no liquid is produced, to obtain a modified curing agent precursor; in step A2, the use amount ratio of the paraformaldehyde, 2-furfurylamine, N,N-dimethylformamide and modified curing agent precursor is 2-3 g:5-7 g:100-120 mL:8-10 g, and the post-treatment step includes: after the reaction is completed, the reaction is cooled to room temperature, and then filtered, and the filtrate is transferred to a rotary evaporator with a temperature of 90-100 DEG C, and rotary evaporation is performed under reduced pressure until no liquid is produced, to obtain a modified curing agent.

[0017] Further, the modified capsule is prepared by the following steps:

[0018] B1, melamine, formaldehyde aqueous solution, heat-conducting composite liquid and deionized water are placed in a reaction kettle and stirred, and an ammonia solution is added to adjust pH = 8-9, and stirred for 15-30 min to obtain a mixed aqueous phase;

[0019] B2, sodium dodecyl sulfate and deionized water are placed in a reaction kettle and stirred, and an acetic acid solution is added to adjust pH = 3-4, and paraffin is added, the reaction kettle is heated to 70-80 DEG C, and stirred for 15-30 min, and the mixed aqueous phase is added dropwise, and reacted for 4-6 h, and the modified capsule precursor is obtained after post-treatment;

[0020] The preparation reaction principle of the modified capsule precursor is:

[0021] During the reaction, melamine reacts with formaldehyde under alkaline conditions to form water-soluble hydroxymethyl melamine prepolymer, paraffin is a hydrophobic solid phase change material that completely melts under heating, and the dispersant is adjusted to an appropriate pH, and then emulsified with the molten paraffin to form an emulsion. Under weak acidic conditions, the hydroxymethyl melamine prepolymer begins to further aggregate on the surface of the hot emulsion system after being added dropwise, and a crosslinking reaction occurs, coating the paraffin droplets. The modified boron nitride and graphene oxide in the heat-conducting composite liquid are embedded in the polymer layer by chemical bonding and hydrogen bonding adsorption to form a composite shell layer, and the modified capsule precursor with paraffin as the core is obtained.

[0022] B3, the modified capsule precursor, ethanol, deionized water and gamma-aminopropyl triethoxysilane are placed in a reaction kettle and stirred, the reaction kettle is heated to 40-50 DEG C, and reacted for 2-4 h, and the modified capsule is obtained after post-treatment.

[0023] The preparation reaction principle of the modified capsule is:

[0024] During the reaction, under the heating condition, the silicon-oxygen bond of γ-aminopropyl triethoxysilane is hydrolyzed into silanol, and the silanol condenses with the hydroxyl group on the surface of the modified capsule precursor to obtain the modified capsule modified by the silane coupling agent.

[0025] Further, in step B1, the amount ratio of the melamine, the formaldehyde aqueous solution, the heat-conducting composite liquid and the deionized water is 2-4 g:6-10 mL:8-10 mL:60-80 mL, the concentration of the ammonia solution is 20-25 wt%, and the concentration of the formaldehyde aqueous solution is 35-40 wt%; in step B2, the amount ratio of the sodium dodecyl sulfate, the deionized water, the paraffin and the mixed aqueous phase is 0.5-1 g:30-50 mL:2-4 g:5-7 mL, the acetic acid solution is an acetic acid aqueous solution with an acetic acid content of 1-5 wt%, and the post-processing step includes: after the reaction is completed, the reaction system is cooled to room temperature, and then the filter cake is washed with ethanol and deionized water for 2-3 times, and then the filter cake is transferred to an oven with a temperature of 50-60 ℃, and dried to constant weight to obtain the modified capsule precursor; in step B3, the amount ratio of the modified capsule precursor, the ethanol, the deionized water and the γ-aminopropyl triethoxysilane is 2-4 g:50-80 mL:10-15 mL:0.5-1 g, and the post-processing step includes: after the reaction is completed, the reaction system is cooled to room temperature, and then the filter cake is washed with ethanol and deionized water for 2-3 times, and then the filter cake is transferred to an oven with a temperature of 50-60 ℃, and dried to constant weight to obtain the modified capsule.

[0026] Further, the heat-conducting composite liquid is prepared by the following steps:

[0027] C1, boron nitride and urea are added to a ball mill, grinding balls are added, and ball milling is performed for 18-20 h, and then the modified boron nitride is obtained by post-processing.

[0028] The preparation reaction principle of the modified boron nitride is:

[0029] During the reaction, under the grinding of the zirconia grinding balls, the boron nitride particles are continuously impacted, sheared and extruded, so that the interlayer van der Waals force of the boron nitride is weakened, and the layer-by-layer peeling into two-dimensional nanosheets is promoted, the urea molecules enter the interlayer of the boron nitride during the ball milling process, and play the role of intercalating agent, and the urea can further expand the interlayer spacing by the intermolecular hydrogen bond and the weak interaction with the surface of the boron nitride, so as to obtain the modified boron nitride.

[0030] C2, the modified boron nitride, graphene oxide and deionized water are placed in a single-neck flask, and ultrasonic dispersion is performed for 1-2 h to obtain the heat-conducting composite liquid.

[0031] Further, in step C1, the weight ratio of the boron nitride, urea and grinding ball is 1-2:4-6:60-80, the grinding ball is composed of zirconium oxide with a diameter of 5-10mm, the rotating speed of the ball mill is 400-500rpm, and the post-treatment step comprises: after the reaction is completed, the grinding ball is removed, suction filtration is performed, the filter cake is washed with deionized water for 2-3 times, and then is transferred to an oven with a temperature of 50-60℃, and dried to constant weight to obtain the modified boron nitride; in step C2, the usage ratio of the modified boron nitride, graphene oxide and deionized water is 5-10g:2-4g:200-300mL.

[0032] The application further provides a preparation method of a high-stability hydrogen energy fuel cell frame material.

[0033] The preparation reaction principle of the frame material is as follows:

[0034] During the reaction, the branched end phenolic hydroxyl groups in the modified curing agent and the amino groups in the modified capsule promote the curing reaction of the epoxy resin and the o-benzene dimethyl resin, and the benzoxazine structure in the modified curing agent ring-opens to form a phenol and amine intermediate under heating, further promoting the curing of the resin.

[0035] Further, in step S1, the auxiliary additive is composed of a plasticizer, an antioxidant, a flame retardant and a lubricant in a mass ratio of 3:1:5:0.5, the plasticizer is one or more of dibutyl phthalate, diisononyl phthalate and dioctyl sebacate, the antioxidant is one or more of 4,4'-thiobis(6-tert-butyl-3-methylphenol), N,N'-diphenyl-p-phenylenediamine and tris(2,4-di-tert-butylphenyl) phosphite, the flame retardant is one or more of antimony trioxide, aluminum hydroxide and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and the lubricant is one or more of oleic acid amide, paraffin wax and polyethylene wax.

[0036] Further, the operation step of the curing comprises: placing the mold in a vacuum drying box with a temperature of 150℃ for 2 hours, then raising the vacuum drying box to 180℃ for 1 hour, and then raising the vacuum drying box to 210℃ for 1 hour to obtain the frame material.

[0037] The application has the following advantages:

[0038] 1. The present invention prepares urea-intercalated modified boron nitride by ball milling, and compounding it with graphene oxide to form a thermally conductive composite liquid. Then, a paraffin core is prepared by emulsion polymerization, and a hydroxymethyl melamine resin and the thermally conductive composite liquid are prepared into a shell. The shell of the modified capsule precursor is modified with a silane coupling agent to obtain a modified capsule. By intercalating urea with boron nitride, polar functional groups such as amino and amide are introduced, thereby increasing the interfacial bonding performance between boron nitride and the substrate in the frame material and improving its mechanical strength. At the same time, the modified boron nitride flakes after ball milling and peeling have a higher specific surface area and a longer interfacial contact path. Together with the graphene oxide, they form a highly thermally conductive and flexible two-dimensional heat transfer channel, thereby solving the problems of local overheating and uneven thermal expansion and contraction of materials caused by heat accumulation in the hydrogen fuel cell frame during operation, extending the service life of the battery module, and facilitating the construction of a continuous heat transfer channel in the frame material, thereby improving its thermal conductivity and high-temperature resistance.

[0039] 2. The present invention prepares paraffin as the core by emulsion polymerization, prepares hydroxymethyl melamine resin and heat-conducting composite liquid into the shell, and modifies the shell of the modified capsule precursor with a silane coupling agent to obtain a modified capsule; paraffin with phase change heat storage characteristics is introduced as the core material, and paraffin can undergo solid-liquid phase change during temperature changes, and has significant heat absorption and slow release capabilities. During the operation of the fuel cell, it can absorb excess heat in a high temperature environment and release stored heat energy at a low temperature, thereby playing a role in buffering thermal shock and balancing thermal stress, reducing the uneven thermal expansion of the material caused by drastic changes in ambient temperature. The shell of the microcapsule is made of hydroxymethyl melamine. The core-shell structure is composed of melamine resin. Hydroxymethyl melamine resin is a thermosetting material with high cross-linking density and excellent thermal stability. It can maintain the density and mechanical integrity of the shell structure under high temperature conditions and avoid thermal cracking and cracking. The core-shell structure design can effectively disperse and absorb thermal stress under repeated hot and cold cycles, block the initiation and expansion of microcracks, and improve the high and low temperature resistance of the frame material. The surface of the modified capsule shell is coupled and modified by γ-aminopropyltriethoxysilane, introducing -Si-OC and Si-O-Si bonds, promoting the curing of the epoxy resin and o-phthalic dimethyl resin matrix, and improving the mechanical strength of the material.

[0040] 3. The present invention prepares a benzoxazine modified curing agent with a hyperbranched structure through an esterification reaction. The hyperbranched structure has a high degree of branching and multiple functional group ends. It can undergo multi-point cross-linking with epoxy resin and o-phthalic acid resin during the curing process to form a three-dimensional dense network structure, thereby improving the tensile strength and impact resistance of the material. The benzoxazine ring structure has a rigid aromatic ring skeleton and a high thermal decomposition temperature, and has good thermal stability. The cross-linked network structure after curing has strong high temperature resistance, which can significantly improve the high temperature resistance of the frame material. DETAILED DESCRIPTION

[0041] The technical solutions of the present application will be described clearly and completely in combination with the embodiments below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0042] The epoxy resin used in the present application is purchased from Zhejiang Zhenghe Silicon Material Co., Ltd., and the brand is 207-35.

[0043] The o-benzene dimethyl resin used in the present application is purchased from Shandong Bai Rong New Material Technology Co., Ltd., the product name is oxygen resin E44, the brand is E-44, the model is 002, and the brand is Bai Rong.

[0044] The 4-dimethylamino pyridine p-toluenesulfonate used in the present application is purchased from Shanghai Yuan Ye Biological Technology Co., Ltd., the article number is S78659, and the model is biochemical reagent.

[0045] The melamine used in the present application is purchased from Guangzhou Hui Xin New Material Technology Co., Ltd., the model is HX-028-9, and the brand is Silk Road Xuefeng (Jade).

[0046] The paraffin used in the present application is purchased from Shandong Zhuoxuan New Material Co., Ltd., the model is zx-12130, and the article number is ZX-SL-001.

[0047] The boron nitride used in the present application is purchased from Qinghe County Chaotai Metal Material Co., Ltd., the brand is 00878, and the particle size is 5um.

[0048] The graphene oxide used in the present application is purchased from Jiangxi Suobang New Material Technology Co., Ltd., the undersize particle size is 4um-0.3nm, and the brand is Suobang New Material.

[0049] Example 1

[0050] The present embodiment provides a preparation method of a modified capsule used for a high-stability hydrogen energy fuel cell frame material, which comprises the following steps:

[0051] Step I, preparation of modified boron nitride

[0052] Weighing: boron nitride 10g and urea 40g are added into a ball mill, 600g of 5mm zirconium oxide is added, the rotation speed of the ball mill is set to 400rpm, and the ball milling is carried out for 18h. After the reaction is completed, the milling balls are removed, and the filter cake is washed with deionized water for 2 times. Then, the filter cake is transferred to an oven with a temperature of 50℃, and dried to constant weight to obtain modified boron nitride.

[0053] Step II, preparation of heat conducting composite liquid

[0054] Weighing: modified boron nitride 50 g, graphene oxide 20 g and deionized water 2000 mL are placed in a single-neck flask, ultrasonic dispersion for 1 h to obtain a heat-conducting composite liquid.

[0055] Example 2

[0056] The present embodiment provides a preparation method of a heat-conducting composite liquid for a modified capsule for a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0057] Step I, preparation of modified boron nitride

[0058] Weighing: boron nitride 15 g and urea 50 g are added to a ball mill, 700 g of 7 mm zirconia is added, the rotation speed of the ball mill is set to 450 rpm, and ball milling is performed for 19 h. After the reaction is completed, the milling balls are removed, suction filtration is performed, the filter cake is washed with deionized water for 3 times, and then transferred to an oven with a temperature of 55°C for drying to constant weight to obtain modified boron nitride.

[0059] Step II, preparation of heat-conducting composite liquid

[0060] Weighing: modified boron nitride 70 g, graphene oxide 30 g and deionized water 2500 mL are placed in a single-neck flask, ultrasonic dispersion for 1.5 h to obtain a heat-conducting composite liquid.

[0061] Example 3

[0062] The present embodiment provides a preparation method of a heat-conducting composite liquid for a modified capsule for a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0063] Step I, preparation of modified boron nitride

[0064] Weighing: boron nitride 20 g and urea 60 g are added to a ball mill, 800 g of 10 mm zirconia is added, the rotation speed of the ball mill is set to 500 rpm, and ball milling is performed for 20 h. After the reaction is completed, the milling balls are removed, suction filtration is performed, the filter cake is washed with deionized water for 3 times, and then transferred to an oven with a temperature of 60°C for drying to constant weight to obtain modified boron nitride.

[0065] Step II, preparation of heat-conducting composite liquid

[0066] Weighing: modified boron nitride 100 g, graphene oxide 40 g and deionized water 3000 mL are placed in a single-neck flask, ultrasonic dispersion for 2 h to obtain a heat-conducting composite liquid.

[0067] Example 4

[0068] The present embodiment provides a preparation method of a modified capsule for a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0069] Step ①, preparation of mixed aqueous phase

[0070] Take: melamine 20 g, 35 wt% formaldehyde solution 60 mL, 80 mL of heat conduction composite liquid and deionized water 600 mL in the reaction kettle stirring, adding 20 wt% ammonia solution to adjust pH = 8, stirring 15 min, get mixed water phase.

[0071] Step 2, preparation of modified capsule precursor

[0072] Take: sodium dodecyl sulfate 5 g and deionized water 300 mL in the reaction kettle stirring, adding 1 wt% acetic acid solution to adjust pH = 3, adding paraffin 20 g, the reaction kettle to 70 ℃, stirring 15 min, drop 50 mL of mixed water phase, incubation reaction 4 h, after the reaction is completed, the reaction system is reduced to room temperature, suction filtration, filter cake is washed with ethanol and deionized water 2 times, transfer to the oven with a temperature of 50 ℃, drying to constant weight, get modified capsule precursor.

[0073] Step 3, preparation of modified capsule

[0074] Take: modified capsule precursor 20 g, 500 mL of ethanol, deionized water 100 mL and 5 g of γ-aminopropyl triethoxysilane in the reaction kettle stirring, the reaction kettle to 40 ℃, incubation reaction 2 h, after the reaction is completed, the reaction system is reduced to room temperature, suction filtration, filter cake is washed with ethanol and deionized water 2 times, transfer to the oven with a temperature of 50 ℃, drying to constant weight, get modified capsule.

[0075] Example 5

[0076] The present embodiment provides a kind of preparation method of high stability hydrogen energy fuel cell frame material modified capsule, including the following steps:

[0077] Step 1, preparation of mixed water phase

[0078] Take: melamine 30 g, 37 wt% formaldehyde solution 80 mL, 90 mL of heat conduction composite liquid and deionized water 700 mL in the reaction kettle stirring, adding 22 wt% ammonia solution to adjust pH = 8.5, stirring 20 min, get mixed water phase.

[0079] Step 2, preparation of modified capsule precursor

[0080] Take: sodium dodecyl sulfate 7 g and deionized water 400 mL in the reaction kettle stirring, adding 35 wt% acetic acid solution to adjust pH = 3.54, adding paraffin 30 g, the reaction kettle to 75 ℃, stirring 20 min, drop 700 mL of mixed water phase, incubation reaction 5 h, after the reaction is completed, the reaction system is reduced to room temperature, suction filtration, filter cake is washed with ethanol and deionized water 3 times, transfer to the oven with a temperature of 55 ℃, drying to constant weight, get modified capsule precursor.

[0081] Step ③, preparation of modified capsules

[0082] Take: modified capsule precursor 30 g, ethanol 650 mL, deionized water 120 mL and γ-aminopropyl triethoxysilane 7 g are placed in a reaction kettle for stirring, the reaction kettle is heated to 45℃, and the reaction is kept for 3 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with ethanol and deionized water for 3 times, and then transferred to an oven with a temperature of 55℃ for drying until the weight is constant to obtain the modified capsules.

[0083] Example 6

[0084] The present embodiment provides a preparation method of a modified capsule for a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0085] Step ①, preparation of mixed aqueous phase

[0086] Take: melamine 40 g, 40 wt% formaldehyde aqueous solution 100 mL, heat-conducting composite liquid 100 mL and deionized water 800 mL are placed in a reaction kettle for stirring, 25 wt% ammonia solution is added to adjust pH=9, and stirring is performed for 30 min to obtain the mixed aqueous phase.

[0087] Step ②, preparation of modified capsule precursor

[0088] Take: sodium dodecyl sulfate 10 g and deionized water 500 mL are placed in a reaction kettle for stirring, 5 wt% acetic acid aqueous solution is added to adjust pH=4, paraffin 40 g is added, the reaction kettle is heated to 80℃, stirring is performed for 30 min, the mixed aqueous phase 70 mL is added dropwise, and the reaction is kept for 6 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with ethanol and deionized water for 3 times, and then transferred to an oven with a temperature of 60℃ for drying until the weight is constant to obtain the modified capsule precursor.

[0089] Step ③, preparation of modified capsules

[0090] Take: modified capsule precursor 40 g, ethanol 800 mL, deionized water 150 mL and γ-aminopropyl triethoxysilane 10 g are placed in a reaction kettle for stirring, the reaction kettle is heated to 50℃, and the reaction is kept for 4 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with ethanol and deionized water for 3 times, and then transferred to an oven with a temperature of 60℃ for drying until the weight is constant to obtain the modified capsules.

[0091] Example 7

[0092] The present embodiment provides a preparation method of a modified curing agent for a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0093] Step ⑴, preparation of modified curing agent precursor

[0094] Take: 4,4-bis (4-hydroxyphenyl) valeric acid 40 g, N, N-dicyclohexyl carbodiimide 10 g, 4-dimethylamino pyridine p-toluene sulfonate 10 g and N, N-dimethyl formamide 800 mL in the reaction kettle stirring, room temperature reaction 20 h, after the reaction is completed, the reaction system is reduced to room temperature, suction filtration, the filtrate is transferred to the rotary evaporator with a temperature of 90℃, rotary evaporation under reduced pressure until no liquid is produced, to obtain the modified curing agent precursor.

[0095] Step 2, preparation of modified curing agent

[0096] Take: paraformaldehyde 20 g, 2-furfurylamine 50 g and N, N-dimethyl formamide 1000 mL in the reaction kettle, stirring 10 min, adding modified curing agent precursor 80 g, the reaction kettle is heated to 85℃, and the reaction is kept for 6 h. After the reaction is completed, the reaction is reduced to room temperature, suction filtration, the filtrate is transferred to the rotary evaporator with a temperature of 90℃, rotary evaporation under reduced pressure until no liquid is produced, to obtain the modified curing agent.

[0097] Example 8

[0098] The present embodiment provides a preparation method of a modified curing agent for a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0099] Step 1, preparation of modified curing agent precursor

[0100] Take: 4,4-bis (4-hydroxyphenyl) valeric acid 50 g, N, N-dicyclohexyl carbodiimide 20 g, 4-dimethylamino pyridine p-toluene sulfonate 15 g and N, N-dimethyl formamide 1000 mL in the reaction kettle stirring, room temperature reaction 22 h, after the reaction is completed, the reaction system is reduced to room temperature, suction filtration, the filtrate is transferred to the rotary evaporator with a temperature of 95℃, rotary evaporation under reduced pressure until no liquid is produced, to obtain the modified curing agent precursor.

[0101] Step 2, preparation of modified curing agent

[0102] Take: paraformaldehyde 25 g, 2-furfurylamine 60 g and N, N-dimethyl formamide 1100 mL in the reaction kettle, stirring 12 min, adding modified curing agent precursor 90 g, the reaction kettle is heated to 90℃, and the reaction is kept for 7 h. After the reaction is completed, the reaction is reduced to room temperature, suction filtration, the filtrate is transferred to the rotary evaporator with a temperature of 95℃, rotary evaporation under reduced pressure until no liquid is produced, to obtain the modified curing agent.

[0103] Example 9

[0104] The present embodiment provides a preparation method of a modified curing agent for a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0105] Step 1, preparation of modified curing agent precursor

[0106] Take 4,4-bis(4-hydroxyphenyl) valeric acid 60 g, N,N-dicyclohexyl carbodiimide 30 g, 4-dimethylamino pyridine p-toluene sulfonate 20 g and N,N-dimethyl formamide 1200 mL into the reaction kettle and stir, react at room temperature for 24 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, and the filtrate is transferred to a rotary evaporator with a temperature of 100 DEG C. The rotary evaporation is carried out under reduced pressure until no liquid is produced. The modified curing agent precursor is obtained.

[0107] Step 2, preparation of modified curing agent

[0108] Take 4,4-bis(4-hydroxyphenyl) valeric acid 60 g, N,N-dicyclohexyl carbodiimide 30 g, 4-dimethylamino pyridine p-toluene sulfonate 20 g and N,N-dimethyl formamide 1200 mL into the reaction kettle and stir, react at room temperature for 24 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, and the filtrate is transferred to a rotary evaporator with a temperature of 100 DEG C. The rotary evaporation is carried out under reduced pressure until no liquid is produced. The modified curing agent precursor is obtained.

[0109] Example 10

[0110] The present embodiment provides a preparation method of a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0111] Mix diisononyl phthalate, N,N'-diphenyl-p-phenylenediamine, aluminum hydroxide and oleic acid amide in a mass ratio of 3:1:5:0.5 to obtain an auxiliary additive, which is ready for use;

[0112] Take 40 parts of epoxy resin, 10 parts of o-benzene dimethyl resin and 8 parts of auxiliary additive into the reaction kettle and stir. The reaction kettle is heated to 100 DEG C and kept for 20 min. 15 parts of modified curing agent and 5 parts of modified capsule are added. The reaction kettle is heated to 100 DEG C and kept for 1 min. The mold is injected. The mold is placed in a vacuum drying oven with a temperature of 150 DEG C and reacted for 2 hours. Then the vacuum drying oven is raised to 180 DEG C and reacted for 1 hour. The frame material is obtained by reacting at 210 DEG C for 1 hour.

[0113] Example 11

[0114] The present embodiment provides a preparation method of a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0115] Mix diisononyl phthalate, N,N'-diphenyl-p-phenylenediamine, aluminum hydroxide and oleic acid amide in a mass ratio of 3:1:5:0.5 to obtain an auxiliary additive, which is ready for use;

[0116] Take by weight parts: 50 parts of epoxy resin, 15 parts of o-phthalic resin and 9 parts of auxiliary additive are placed in the reaction kettle and stirred, the reaction kettle is heated to 105℃, and the reaction is kept for 25 min, 20 parts of modified curing agent and 7 parts of modified capsule are added, the reaction kettle is heated to 105℃, and the stirring is kept for 3 min, then the mold is injected, the mold is reacted in the vacuum drying oven at a temperature of 150℃ for 2 hours, then the vacuum drying oven is raised to 180℃ for 1 hour, and reacted at 210℃ for 1 hour to obtain the frame material.

[0117] Example 12

[0118] The embodiment provides a preparation method of a high-stability hydrogen energy fuel cell frame material, comprising the following steps:

[0119] The diisononyl phthalate, N,N'-diphenyl-p-phenylenediamine, aluminum hydroxide and oleic acid amide are uniformly mixed according to a mass ratio of 3:1:5:0.5 to obtain an auxiliary additive, which is ready for use;

[0120] Take by weight parts: 60 parts of epoxy resin, 20 parts of o-phthalic resin and 10 parts of auxiliary additive are placed in the reaction kettle and stirred, the reaction kettle is heated to 110℃, and the reaction is kept for 30 min, 25 parts of modified curing agent and 10 parts of modified capsule are added, the reaction kettle is heated to 110℃, and the stirring is kept for 5 min, then the mold is injected, the mold is reacted in the vacuum drying oven at a temperature of 150℃ for 2 hours, then the vacuum drying oven is raised to 180℃ for 1 hour, and reacted at 210℃ for 1 hour to obtain the frame material.

[0121] Comparative Example 1

[0122] The difference between the comparative example and example 12 lies in that the preparation of the mixed water phase in step ① is cancelled.

[0123] Comparative Example 2

[0124] The difference between the comparative example and example 12 lies in that the preparation of the modified capsule precursor in step ② is cancelled.

[0125] Comparative Example 3

[0126] The difference between the comparative example and example 12 lies in that the modified capsule precursor is used instead of the modified capsule in the preparation of the frame material.

[0127] Comparative Example 4

[0128] The difference between the comparative example and example 12 lies in that the modified curing agent precursor is used instead of the modified curing agent in the preparation of the frame material.

[0129] Performance test:

[0130] The Izod impact strength of the battery frame materials prepared from Examples 10-12 and Comparative Examples 1-4 was determined according to the standard GB / T 1843-2008 "Determination of Izod Impact Strength of Plastics";

[0131] The tensile strength of the battery frame materials prepared from Examples 10-12 and Comparative Examples 1-4 was tested according to the standard GB / T 528-2009 "Determination of Tensile Stress-Strain Properties of Vulcanized or Thermoplastic Rubber";

[0132] The thermal conductivity of the battery frame materials prepared from Examples 10-12 and Comparative Examples 1-4 was tested according to the standard GB / T 42919.1-2023 "Determination of Thermal Conductivity and Thermal Diffusivity of Plastics Part 1: General Principles", and the specific data are shown in Table 1.

[0133] Table 1 - Performance test data table of each sample

[0134]

[0135]

[0136] The battery frame materials prepared from Examples 10-12 and Comparative Examples 1-4 were treated at high temperature according to the standard GB / T 2423.102-2008 "Environmental Testing of Electrical and Electronic Products Part 2: Test Methods Test: Temperature (Low, High) / Low Pressure / Vibration (Sine) Synthesis", and the tensile strength of the materials was tested according to the standard GB / T 528-2009, and the Izod impact strength of the materials was tested according to the standard GB / T 1843-2008, and the specific data are shown in Table 2.

[0137] Table 2 - Performance test data table of each sample after high temperature treatment

[0138]

[0139] The battery frame materials prepared from Examples 10-12 and Comparative Examples 1-4 were treated at low temperature according to the standard GB / T 2423.102-2008 "Environmental Testing of Electrical and Electronic Products Part 2: Test Methods Test: Temperature (Low, High) / Low Pressure / Vibration (Sine) Synthesis", and the tensile strength of the materials was tested according to the standard GB / T 528-2009, and the Izod impact strength of the materials was tested according to the standard GB / T 1843-2008, and the specific data are shown in Table 3.

[0140] Table 3 - Performance test data table of each sample after low temperature treatment

[0141]

[0142] Data analysis:

[0143] Comparative analysis of the data in Tables 1-3 above, the cantilever beam impact strength of the hydrogen energy fuel cell frame material prepared by the present application is 16.3kJ·m -2 , the tensile strength is 89.2MPa and the thermal conductivity is 1.4W·(m·K) -1 , after high temperature treatment, the cantilever beam impact strength of the material is 15.4kJ·m -2 and the tensile strength is 79.3MPa, after low temperature treatment, the cantilever beam impact strength of the material is 14.7kJ·m -2 and the tensile strength is 75.3MPa;

[0144] By comparing the data of Comparative Example 1 and Example 12, it is found that the cantilever beam impact strength, tensile strength and thermal conductivity of Comparative Example 1 are significantly reduced, and the mechanical strength after high temperature treatment is significantly reduced, which shows that the urea intercalated modified boron nitride is prepared by the ball milling method, and the thermal conductive composite liquid is prepared by compounding the modified boron nitride with graphene oxide, the shell layer is prepared by using paraffin as the core, hydroxymethyl melamine resin and the thermal conductive composite liquid, and the shell layer of the modified capsule precursor is modified by using silane coupling agent, to obtain the modified capsule; by introducing polar functional groups such as amino and amide through urea intercalated boron nitride, the interfacial bonding performance of boron nitride and the base material in the frame material is increased, and the mechanical strength is improved, at the same time, the modified boron nitride after ball milling and exfoliation has higher specific surface area and longer interface contact path, and together with graphene oxide, it forms a high thermal conductive and flexible two-dimensional heat transfer channel, solves the problems of local overheating caused by heat accumulation, uneven thermal expansion and contraction of hydrogen fuel cell frame during operation, prolongs the service life of the battery module, and helps to build a continuous heat transfer channel in the frame material, and improves the thermal conductivity and high temperature resistance of the frame material;

[0145] It is found by comparing and analyzing the table data of Comparative Example 2 and Example 12 that the mechanical strength of Comparative Example 2 after high-temperature treatment and low-temperature treatment decreases significantly, which indicates that the modified capsule is prepared by the emulsion polymerization method, the paraffin is used as the core, the hydroxymethyl melamine resin and the heat-conducting composite liquid are used to prepare the shell layer, and the shell layer of the modified capsule precursor is modified by the silane coupling agent, the paraffin with phase change heat storage characteristics is introduced as the core layer material, the paraffin can change from solid to liquid in the temperature change process, has significant heat absorption and slow release capacity, can absorb excess heat in the high-temperature environment and release stored heat energy in the low-temperature environment in the fuel cell operation process, thereby buffering the thermal shock and balancing the thermal stress, reducing the thermal expansion unevenness in the material caused by the sharp change of the environmental temperature difference, the shell layer of the microcapsule is composed of the hydroxymethyl melamine resin, the hydroxymethyl melamine resin is a thermosetting material, has high crosslinking density and excellent thermal stability, can maintain the compactness and mechanical integrity of the shell structure under the high-temperature condition, avoids the thermal cracking and cracking phenomenon, and the core-shell structure design can effectively disperse and absorb the thermal stress, block the initiation and expansion of the microcracks, and improve the high-low temperature resistance of the frame material.

[0146] It is found by comparing and analyzing the table data of Comparative Example 3 and Example 12 that the cantilever beam impact strength and the tensile strength of Comparative Example 3 decrease significantly, which indicates that the surface of the modified capsule shell layer is modified by the γ-aminopropyl triethoxysilane, the -Si-O-C and Si-O-Si bonds are introduced, the curing of the epoxy resin and the o-benzene dimethyl resin matrix is promoted, and the mechanical strength of the material is improved.

[0147] It is found by comparing and analyzing the table data of Comparative Example 4 and Example 12 that the cantilever beam impact strength and the tensile strength of Comparative Example 4 decrease significantly, and the mechanical strength after high-temperature treatment decreases significantly, which indicates that the benzoxazine modified curing agent with hyperbranched structure is prepared by the esterification reaction, the hyperbranched structure has high branching and multiple functional end groups, can occur multi-point crosslinking with the epoxy resin and the o-benzene dimethyl resin in the curing process, form a three-dimensional dense network structure, improve the tensile strength and impact resistance of the material, the benzoxazine ring structure has a rigid aromatic skeleton and high thermal cracking temperature, has good thermal stability, and the crosslinking network structure after curing has strong high-temperature resistance, which can significantly improve the high-temperature resistance of the frame material.

[0148] The above content is only an example and description of the structure of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific examples, as long as the modifications or supplements or replacements do not deviate from the structure of the present application or exceed the scope defined by the present application, which shall belong to the protection scope of the present application.

[0149] In the description of the specification, reference to "one embodiment", "an example", "a specific example" or the like means that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "an example", "a specific example" or the like in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0150] The preferred embodiments of the application disclosed above are only to help explain the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments. Obviously, many modifications and variations can be made in light of the contents of the specification. The specification selects and specifically describes these embodiments in order to better explain the principles and practical application of the application, so that those skilled in the art can well understand and utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. A highly stable hydrogen fuel cell frame material, characterized in that: The invention comprises the following components in parts by weight: 40-60 parts of epoxy resin, 10-20 parts of o-phthalic dimethyl resin, 15-25 parts of modified curing agent, 5-10 parts of modified capsule and 8-10 parts of auxiliary additives; The auxiliary additives are composed of a plasticizer, an antioxidant, a flame retardant and a lubricant in a mass ratio of 3:1:5:0.

5.

2. A highly stable hydrogen fuel cell frame material according to claim 1, characterized in that: The modified curing agent is prepared by the following steps: A1. Place 4,4-bis(4-hydroxyphenyl)valeric acid, N,N-dicyclohexylcarbodiimide, 4-dimethylaminopyridine p-toluenesulfonate, and N,N-dimethylformamide in a reaction kettle, stir, react at room temperature for 20-24 hours, and post-treat to obtain a modified curing agent precursor; A2. Place paraformaldehyde, 2-furylamine and N,N-dimethylformamide in a reactor, stir for 10-15 minutes, add a modified curing agent precursor, heat the reactor to 85-95°C, keep the temperature for 6-8 hours, and post-treat to obtain a modified curing agent.

3. A highly stable hydrogen fuel cell frame material according to claim 2, characterized in that: In step A1, the amount ratio of the 4,4-bis(4-hydroxyphenyl)valeric acid, N,N-dicyclohexylcarbodiimide, 4-dimethylaminopyridine toluenesulfonate and N,N-dimethylformamide is 4-6 g:1-3 g:1-2 g:80-120 mL; in step A2, the amount ratio of the paraformaldehyde, 2-furfurylamine, N,N-dimethylformamide and modified curing agent precursor is 2-3 g:5-7 g:100-120 mL:8-10 g.

4. A highly stable hydrogen fuel cell frame material according to claim 1, characterized in that: The modified capsule is prepared by the following steps: B1. Place melamine, formaldehyde aqueous solution, thermal conductive composite liquid and deionized water in a reaction kettle and stir, add ammonia aqueous solution to adjust the pH to 8-9, and stir for 15-30 minutes to obtain a mixed aqueous phase; B2. Sodium lauryl sulfate and deionized water were placed in a reaction kettle and stirred. Acetic acid solution was added to adjust the pH to 3-4. Paraffin was added. The temperature of the reaction kettle was raised to 70-80° C. and stirred for 15-30 min. The mixed aqueous phase was added dropwise. The mixture was kept warm for 4-6 h and then post-treated to obtain a modified capsule precursor. B3. Place the modified capsule precursor, ethanol, deionized water and γ-aminopropyltriethoxysilane in a reactor and stir. Heat the reactor to 40-50° C. and keep the temperature for 2-4 hours. Post-treat to obtain the modified capsule.

5. A highly stable hydrogen fuel cell frame material according to claim 4, characterized in that: In step B1, the amount ratio of melamine, formaldehyde aqueous solution, thermal conductive composite liquid and deionized water is 2-4g:6-10mL:8-10mL:60-80mL, the concentration of the ammonia aqueous solution is 20-25wt%, and the concentration of the formaldehyde aqueous solution is 35-40wt%; in step B2, the amount ratio of sodium lauryl sulfate, deionized water, paraffin and mixed aqueous phase is 0.5-1g:30-50mL:2-4g:5-7mL, and the acetic acid solution is a 1-5wt% acetic acid aqueous solution; in step B3, the amount ratio of the modified capsule precursor, ethanol, deionized water and γ-aminopropyltriethoxysilane is 2-4g:50-80mL:10-15mL:0.5-1g.

6. A highly stable hydrogen fuel cell frame material according to claim 4, characterized in that: The thermal conductive composite liquid is prepared by the following steps: C1. Add boron nitride and urea into a ball mill, add grinding balls, and ball mill for 18-20 hours, followed by post-processing to obtain modified boron nitride; C2. Place modified boron nitride, graphene oxide and deionized water in a single-necked bottle and ultrasonically disperse for 1-2 hours to obtain a thermal conductive composite liquid.

7. A highly stable hydrogen fuel cell frame material according to claim 6, characterized in that: In step C1, the weight ratio of the boron nitride, urea, and grinding balls is 1-2:4-6:60-80, and the grinding balls are composed of zirconium oxide with a diameter of 5-10 mm; in step C2, the amount ratio of the modified boron nitride, graphene oxide, and deionized water is 5-10 g:2-4 g:200-300 mL.

8. The method for preparing a high-stability hydrogen fuel cell frame material according to any one of claims 1 to 7, characterized in that: The preparation method of the high-stability hydrogen energy fuel cell frame material is as follows: epoxy resin, o-phthalic dimethyl resin and auxiliary additives are placed in a reactor and stirred, the reactor is heated to 100-110° C., and the reaction is carried out at this temperature for 20-30 minutes, a modified curing agent and a modified capsule are added, the reactor is heated to 100-110° C., the reaction is carried out at this temperature for 1-5 minutes, the modified curing agent and the ... injected into a mold, and the modified curing agent and the modified capsule are cured to obtain the frame material.

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