Ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, and preparation method and application thereof

Abstract

The present application relates to the technical field of inorganic non-metallic material preparation, in particular to a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, a preparation method and application thereof. The preparation method of the ceramic and carbonaceous reinforced carbon-based composite bipolar plate material comprises the following steps: mixing ceramic reinforcing phase, carbonaceous reinforcing phase and pitch compound as raw materials, and performing thermal polycondensation reaction; performing solvent extraction and solid-liquid separation to obtain pitch mesophase carbon microsphere in-situ coated ceramic and carbonaceous reinforcing phase precursor; performing hot-pressing of the pitch mesophase carbon microsphere in-situ coated ceramic and carbonaceous reinforcing phase precursor to obtain a green body; and performing sintering and carbonization treatment and impregnation treatment on the green body to obtain the ceramic and carbonaceous reinforced carbon-based composite bipolar plate material. The ceramic and carbonaceous reinforced carbon-based composite bipolar plate material with excellent mechanical properties, electrical conductivity and electrochemical corrosion resistance is prepared by a low-cost, short-process and efficient process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inorganic non-metallic material preparation, in particular to a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material and a preparation method and application thereof. BACKGROUND

[0002] A proton exchange membrane fuel cell (PEMFC) is a power generation device that directly converts chemical energy stored in fuel and oxidants into electrical energy without combustion. As a main component of a proton exchange membrane fuel cell, the material and performance of a bipolar plate directly determine the use performance, operating life and preparation cost of a cell stack. Carbon-based materials have good electrical conductivity, thermal conductivity and corrosion resistance, and are commonly used as bipolar plates for proton exchange membrane fuel cells. However, as a bipolar plate material, it generally has high porosity, poor processing mechanical properties, high resistivity and is prone to electrochemical oxidation corrosion.

[0003] A composite carbon-based bipolar plate material is a composite material with polymer resin, pitch, mesocarbon microbeads and other organic carbon precursors as a bonding phase, and carbonaceous materials (such as graphite, carbon fibers and graphene) or ceramic materials (such as silicon carbide and boron carbide) as a reinforcing phase. When mesocarbon microbeads (MCMB) are used as the carbon matrix and the bonding phase and the reinforcing phase are compounded, the mesocarbon microbeads and the reinforcing phase are mixed and subjected to hot pressing, sintering and other steps for bonding and compounding. However, the reinforcing phase particles and the mesocarbon microbead structure are still independent individuals, and there are problems such as raw material agglomeration, uneven compounding and insufficient bonding between the two phases, which result in small contact area between the particles and large pores, seriously affecting the mechanical and electrochemical properties of the material. Therefore, how to prepare a carbon-based composite bipolar plate material with excellent mechanical properties, electrical conductivity and electrochemical corrosion resistance is still a problem to be solved. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defects of poor mechanical properties, electrical conductivity and electrochemical corrosion resistance of the existing composite carbon-based bipolar plate material, and to provide a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material and a preparation method and application thereof to solve the above problems.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] In a first aspect, the present application provides a preparation method of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, comprising:

[0007] The ceramic reinforcing phase, the carbonaceous reinforcing phase and the pitch compound are mixed and subjected to a thermal polycondensation reaction, and pitch mesocarbon microbeads in-situ coated with a ceramic and carbonaceous reinforcing phase precursor are obtained through solvent extraction and solid-liquid separation.

[0008] The pitch mesophase carbon microsphere in-situ coated ceramic and carbonaceous reinforcing phase precursor is hot-pressed to obtain a green body;

[0009] The green body is sintered and carbonized, and impregnated to obtain a ceramic and carbonaceous reinforcing carbon-based composite bipolar plate material.

[0010] Preferably, the pitch compound includes at least one of coal pitch, petroleum pitch, naphthalene pitch, and secondary refined pitch;

[0011] And / or, the carbonaceous reinforcing phase includes at least one of graphite, expanded graphite, carbon black, carbon fiber, and graphene;

[0012] And / or, the particle size of the carbonaceous reinforcing phase is 0.02-10 µm;

[0013] And / or, the ceramic reinforcing phase includes at least one of titanium boride, titanium carbide, titanium nitride, and boron carbide;

[0014] And / or, the particle size of the ceramic reinforcing phase is 0.1-10 µm;

[0015] And / or, the mass ratio of the pitch compound, the ceramic reinforcing phase, and the carbonaceous reinforcing phase is 20:(1-6):(0.1-3).

[0016] Preferably, the mixing process is: stirring at a speed of 1500-2500 r / min at a temperature of 120-180 ℃ for 0.5-2 h;

[0017] And / or, the temperature of the thermal polycondensation reaction is 380-420 ℃;

[0018] And / or, the temperature rising rate of the thermal polycondensation reaction is 1-5 ℃ / min;

[0019] And / or, the stirring rate of the thermal polycondensation reaction is 300-800 r / min;

[0020] And / or, the duration of the thermal polycondensation reaction is 2-4 h;

[0021] And / or, the atmosphere of the thermal polycondensation reaction is inert atmosphere;

[0022] And / or, a pitch modifier is further added during the thermal polycondensation reaction; the pitch modifier is a resin-based modifier, preferably at least one of phenolic resin and epoxy resin; the mass ratio of the pitch modifier to the pitch compound is (0.5-4):20;

[0023] And / or, the thermal polycondensation reaction is followed by crushing;

[0024] And / or, the organic solvent used in the solvent extraction includes at least one of tetrahydrofuran, toluene, pyridine, quinoline, dichloromethane, trichloroethylene, and wash oil;

[0025] And / or, the solid-liquid separation includes at least one of filtration, sedimentation, and centrifugation.

[0026] Preferably, the forming temperature of the hot-press forming is 320-380 ℃.

[0027] And / or, the forming pressure of the hot-press forming is 30-80 MPa.

[0028] And / or, the pressure holding time of the hot-press forming is 8-15 min.

[0029] And / or, the hot-press forming is further subjected to a sieving treatment before the hot-press forming; optionally, the mesh number of the sieving treatment is 300 mesh.

[0030] Preferably, the process of the sintering and carbonization treatment is: first, increasing the temperature to 400-450 ℃ at a rate of 1-5 ℃ / min and holding for 1-2 h, and then, continuously increasing the temperature to 900-1400 ℃ at a rate of 1-2 ℃ / min and holding for 2-5 h.

[0031] And / or, the atmosphere of the sintering and carbonization treatment is inert atmosphere.

[0032] Preferably, the impregnating agent used in the process of the impregnating treatment is thermosetting phenolic resin or / and asphalt;

[0033] And / or, the impregnating treatment is performed under negative pressure; the negative pressure is 0.1-10 kPa.

[0034] And / or, the time of the impregnating treatment is 5-10 h.

[0035] And / or, the impregnating treatment is followed by cleaning with an organic solvent.

[0036] And / or, the impregnating treatment is further followed by a curing treatment.

[0037] Preferably, the organic solvent includes at least one of ethanol and acetone.

[0038] And / or, when the impregnating agent is thermosetting phenolic resin, the temperature of the curing treatment is 160-190 ℃, and the time of the curing treatment is 1-2 h.

[0039] And / or, when the impregnating agent is asphalt, the asphalt quinoline insoluble content is not more than 0.1%, the softening point is 50-100 ℃, the temperature of the impregnating treatment is 100-120 ℃, the temperature of the curing treatment is 380-420 ℃, and the time of the curing treatment is 2-3 h.

[0040] In a second aspect, the present application also provides a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, which is prepared by the above-mentioned method for preparing a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material.

[0041] In a third aspect, the present application also provides the use of the above-mentioned ceramic and carbonaceous reinforced carbon-based composite bipolar plate material in a fuel cell or a water electrolysis hydrogen production stack.

[0042] The technical scheme of the present application has the following advantages:

[0043] 1. A method for preparing a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, comprising: mixing a ceramic reinforcing phase, a carbonaceous reinforcing phase and a pitch-based compound as raw materials and performing a thermal polycondensation reaction, to obtain a mesocarbon microbead intermediate phase in situ coated ceramic and carbonaceous reinforcing phase precursor through solvent extraction and solid-liquid separation; performing hot pressing on the mesocarbon microbead intermediate phase in situ coated ceramic and carbonaceous reinforcing phase precursor to obtain a green body; and performing sintering and carbonization treatment and impregnation treatment on the green body to obtain the ceramic and carbonaceous reinforced carbon-based composite bipolar plate material. In the present application, ceramic and carbonaceous are used as reinforcing phases, and mesocarbon microbeads prepared by thermal polycondensation of a pitch-based compound are used as a bonding phase. By using the reinforcing phase as a heterogeneous nucleation core of the thermal polycondensation reaction, the mesocarbon microbead coated reinforcing phase structure is generated in situ, so that the carbon matrix (mesocarbon microbeads generated by thermal polycondensation of pitch) and the reinforcing phase (ceramic and carbonaceous) form a more uniform and compact composite structure, thereby significantly improving the mechanical and electrochemical properties of the bipolar plate material. Through the above technical means, the carbon-based composite bipolar plate material with excellent mechanical properties, electrical conductivity and electrochemical corrosion resistance is prepared by a low-cost, short-flow and efficient process.

[0044] 2. In the method for preparing a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, the ceramic reinforcing phase is preferably titanium boride, which has good electrical conductivity and catalyzes graphitization during the carbonization process of the mesocarbon microbead precursor, thereby significantly improving the electrical conductivity and electrochemical corrosion resistance of the carbon-based bipolar plate. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present application or the technical scheme in the prior art, the drawings needed in the following specific embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0046] Figure 1is a SEM morphology diagram of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material prepared in Example 1 of the present application.

[0047] Figure 2 is a SEM morphology diagram of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0048] The following examples are provided to better enable those skilled in the art to further understand the present application, and are not intended to limit the scope of the present application, and do not constitute a limitation on the scope of the present application and the scope of protection, anyone who is inspired by the present application or combines the present application with other prior art features to obtain any product identical or similar to the present application, falls within the scope of protection of the present application.

[0049] The specific experimental steps or conditions are not specified in the examples, and can be performed according to the conventional experimental steps described in the literature or the operation or conditions. The reagents or instruments used are not specified by the manufacturer, and are conventional reagent products that can be obtained by purchase.

[0050] Example 1

[0051] The present embodiment provides a preparation method of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, and the specific steps are as follows:

[0052] 100 g of medium temperature coal pitch, 5 g of phenolic resin, 10 g of titanium boride with a particle size of 5 µm and 5 g of graphite with a particle size of 3 µm were mixed uniformly and then placed in a high-temperature reaction kettle and heated to 150 ℃. After the pitch was completely melted, it was dispersed at a high speed of 1500 r / min for 0.5 h. Under the conditions of argon protection and a stirring rate of 500 r / min, the temperature was raised to 400 ℃ at a rate of 5 ℃ / min, and the heat polycondensation reaction was carried out for 2 h. After cooling, a composite mesophase pitch was obtained. After crushing, a Soxhlet extractor was used with tetrahydrofuran as the solvent to extract the soluble components in the composite mesophase pitch until the solvent was nearly colorless. After filtration and separation, a ceramic and carbonaceous reinforced phase precursor coated with asphalt mesophase carbon microspheres in situ was obtained, and the SEM morphology is as shown in Figure 1The precursor was passed through a 300-mesh sieve, 15 g was weighed into a mold, heated to 350 ℃ under a preloading pressure of 2 MPa, pressurized to 40 MPa, and held for 10 min to obtain a green body of the bipolar plate; the green body was laid flat and buried in a crucible filled with graphite fragments, and heated to 400 ℃ at a rate of 5 ℃ / min under inert atmosphere protection in a high-temperature furnace, and held for 1 h; continued heating to 900 ℃ at a rate of 2 ℃ / min, and held for 2 h to complete carbonization; the carbonized composite bipolar plate sample was immersed in a thermosetting phenolic resin, placed in a vacuum drying oven, and immersed for 5 h under a negative pressure of 10 kPa at room temperature, then the surface residual resin was cleaned with an ethanol solvent, and placed in a heating furnace and heated to 160 ℃, and held for 2 h to complete curing to obtain a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, and the SEM morphology is as shown in Figure 2 .

[0053] Example 2

[0054] The present embodiment provides a preparation method of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, and the specific steps are as follows:

[0055] 100 g of medium-temperature coal tar pitch, 10 g of phenolic resin, 15 g of titanium boride with a particle size of 5 µm, 10 g of graphite with a particle size of 5 µm, and 3 g of conductive carbon black were weighed and uniformly mixed, and then placed in a high-temperature reaction kettle and heated to 150 ℃; after the pitch was completely melted, it was dispersed at a high speed of 1500 r / min for 0.5 h; under the protection of argon and at a stirring rate of 500 r / min, the temperature was raised to 400 ℃ at a rate of 5 ℃ / min, and the heat polycondensation reaction was carried out for 2 h; after cooling, a composite mesophase pitch was obtained; after crushing, a Soxhlet extractor was used to extract the soluble components in the composite mesophase pitch with tetrahydrofuran as the solvent until the solvent was nearly colorless; after filtration and separation, an asphalt mesophase carbon microsphere in-situ coated ceramic and carbonaceous reinforced phase precursor was obtained; the precursor was passed through a 300-mesh sieve, 15 g was weighed into a mold, heated to 350 ℃ under a preloading pressure of 2 MPa, pressurized to 60 MPa, and held for 10 min to obtain a green body of the bipolar plate; the green body was laid flat and buried in a crucible filled with graphite fragments, and heated to 400 ℃ at a rate of 5 ℃ / min under inert atmosphere protection in a high-temperature furnace, and held for 1 h; continued heating to 1000 ℃ at a rate of 2 ℃ / min, and held for 2 h to complete carbonization; the carbonized composite bipolar plate sample was immersed in a thermosetting phenolic resin, placed in a vacuum drying oven, and immersed for 5 h under a negative pressure of 10 kPa at room temperature, then the surface residual resin was cleaned with an ethanol solvent, and placed in a heating furnace and heated to 160 ℃, and held for 2 h to complete curing to obtain a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material.

[0056] Example 3

[0057] The embodiment provides a preparation method of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, and specific steps are as follows.

[0058] 100 g of medium-temperature coal pitch, 10 g of phenolic resin, 15 g of titanium boride with a particle size of 5 μm, 5 g of graphite with a particle size of 5 μm and 5 g of expanded graphite with a particle size of 10 μm are weighed respectively, uniformly mixed, and then placed into a high-temperature reaction kettle and heated to 150 ℃; after the pitch is completely melted, high-speed dispersion is performed at a rotation speed of 1500 r / min for 0.5 h; under the conditions of argon protection and a stirring speed of 500 r / min, the temperature is increased to 380 ℃ at a speed of 5 ℃ / min, and heat polycondensation is performed for 2 h; after cooling, a composite mesophase pitch is obtained; after crushing, a Soxhlet extractor is used to extract the soluble components in the composite mesophase pitch to near colorless with tetrahydrofuran as a solvent; after filtration and separation, a pitch mesocarbon microbead in-situ coated ceramic and carbonaceous reinforcing phase precursor is obtained; the precursor is sieved through a 300-mesh sieve, 15 g of the precursor is loaded into a mold, and the temperature is increased to 350 ℃ under a preloading pressure of 2 MPa; the pressure is increased to 80 MPa, and pressure retention is performed for 10 min to obtain a bipolar plate green body; the green body is laid and buried in a crucible filled with graphite fragments, and the temperature is increased to 400 ℃ at a speed of 5 ℃ / min under the condition of inert atmosphere protection in a high-temperature furnace; the temperature is continuously increased to 1200 ℃ at a speed of 2 ℃ / min, and heat preservation is performed for 2 h to complete carbonization; the carbonized composite bipolar plate sample is immersed in thermosetting phenolic resin, and then placed into a vacuum drying box; after immersion for 5 h under the condition of room temperature and a negative pressure of 10 kPa, the surface residual resin is cleaned with an ethanol solvent; and then the sample is placed in a heating furnace and heated to 160 ℃, and heat preservation is performed for 2 h to complete curing, so that the ceramic and carbonaceous reinforced carbon-based composite bipolar plate material is obtained.

[0059] Embodiment 4

[0060] The embodiment provides a preparation method of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, and specific steps are as follows:

[0061] 100 g of medium-temperature coal pitch, 10 g of phenolic resin, 20 g of titanium boride with a particle size of 3 µm, and 1 g of nanometer carbon fiber were weighed and uniformly mixed, and then placed in a high-temperature reaction kettle and heated to 150 ℃. After the pitch was completely melted, it was dispersed at a high speed of 1500 r / min for 0.5 h. Under the conditions of argon protection and a stirring rate of 500 r / min, the temperature was increased to 400 ℃ at a rate of 5 ℃ / min, and the heat polycondensation reaction was carried out for 2 h. After cooling, a composite mesophase pitch was obtained. After crushing, the soluble components in the composite mesophase pitch were extracted with a Soxhlet extractor using tetrahydrofuran as the solvent until the solvent was nearly colorless. After filtration and separation, a precursor of in-situ coated ceramic and carbonaceous reinforcing phase in pitch mesocarbon microbeads was obtained. The precursor was sieved through a 300-mesh sieve, and 15 g of the precursor was loaded into a mold. Under a preloading pressure of 2 MPa, the temperature was increased to 350 ℃, and the pressure was increased to 60 MPa, and the pressure was maintained for 10 min to obtain a green body of the bipolar plate. The green body was placed and buried in a graphite-filled crucible, and the temperature was increased to 400 ℃ at a rate of 5 ℃ / min under the protection of an inert atmosphere in a high-temperature furnace, and the temperature was maintained for 1 h. The temperature was further increased to 1200 ℃ at a rate of 2 ℃ / min, and the temperature was maintained for 2 h to complete the carbonization. The carbonized composite bipolar plate sample was immersed in a thermosetting phenolic resin, and then placed in a vacuum drying box under the condition of room temperature and a negative pressure of 10 kPa for 5 h. After the surface residual resin was cleaned with an ethanol solvent, the sample was placed in a heating furnace and heated to 160 ℃, and the temperature was maintained for 2 h to complete the curing, thereby obtaining a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material.

[0062] Example 5

[0063] The present embodiment provides a preparation method of a ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, and the specific steps are as follows:

[0064] Take 100 g of medium temperature coal pitch, 5 g of epoxy resin, 5 g of titanium boride with a particle size of 3 µm, and 15 g of graphite with a particle size of 5 µm, respectively, mix them uniformly, and then put them into a high-temperature reaction kettle and heat them to 120 ℃. After the pitch is completely melted, disperse them at a speed of 1500 r / min for 2 h. Under the conditions of argon protection and a stirring speed of 300 r / min, heat them to 380 ℃ at a rate of 1 ℃ / min, and keep the temperature for 4 h to perform a thermal polycondensation reaction. After cooling, a composite mesophase pitch is obtained. After crushing, use a Soxhlet extractor to extract the soluble components in the composite mesophase pitch with dichloromethane as the solvent until the solvent is nearly colorless. After centrifugal separation, a precursor of ceramic and carbonaceous reinforcing phase in-situ coated on mesocarbon microbeads is obtained. After sieving the precursor through a 300-mesh sieve, take 15 g of the precursor and put it into a mold. Under a preloading pressure of 2 MPa, heat it to 320 ℃, pressurize it to 80 MPa, and keep the pressure for 8 min to obtain a green body of a bipolar plate. Place the green body flat in a crucible filled with graphite fragments, and heat it to 400 ℃ at a rate of 1 ℃ / min under the protection of an inert atmosphere in a high-temperature furnace, and keep the temperature for 1 h. Continue to heat it to 900 ℃ at a rate of 2 ℃ / min, and keep the temperature for 5 h to complete carbonization. After carbonizing the composite bipolar plate sample, immerse it in a thermosetting phenolic resin, put it into a vacuum drying box, and immerse it for 10 h under the condition of room temperature and a negative pressure of 10 kPa. After cleaning the surface residual resin with acetone solvent, place it in a heating furnace, heat it to 190 ℃, keep the temperature for 1 h to complete curing, and obtain a ceramic and carbonaceous reinforcing carbon-based composite bipolar plate material.

[0065] Example 6

[0066] The present embodiment provides a preparation method of a ceramic and carbonaceous reinforcing carbon-based composite bipolar plate material, and the specific steps are as follows:

[0067] 100 g of petroleum pitch, 20 g of phenolic resin, 20 g of titanium boride with a particle size of 8 μm, and 2 g of conductive carbon black with a particle size of 0.02 μm were weighed respectively, uniformly mixed, and then placed in a high-temperature reaction kettle and heated to 180 ℃. After the pitch was completely melted, high-speed dispersion was performed at a rotation speed of 2500 r / min for 1 h. Under the conditions of argon protection and a stirring rate of 800 r / min, the temperature was increased to 420 ℃ at a rate of 5 ℃ / min, and heat polycondensation was performed for 2 h. After cooling, a composite mesophase pitch was obtained. After crushing, a Soxhlet extractor was used to extract the soluble components in the composite mesophase pitch with tetrahydrofuran as the solvent until the solvent was nearly colorless. After filtration and separation, a precursor of in-situ coated ceramic and carbonaceous reinforcing phase in pitch mesocarbon microbeads was obtained. The precursor was sieved through a 300-mesh sieve, 15 g of the precursor was placed in a mold, and the temperature was increased to 380 ℃ under a preloading pressure of 2 MPa. The pressure was increased to 30 MPa, and pressure retention was performed for 15 min to obtain a green body of a bipolar plate. The green body was placed and buried in a crucible filled with graphite fragments, and the temperature was increased to 450 ℃ at a rate of 5 ℃ / min under the protection of an inert atmosphere in a high-temperature furnace. The temperature was further increased to 1400 ℃ at a rate of 2 ℃ / min, and carbonization was completed after 2 h of heat preservation. The carbonized composite bipolar plate sample was immersed in impregnated pitch (the quinoline insoluble content was 0.1%, and the softening point was 85 ℃). After being placed in a vacuum drying box under the conditions of 110 ℃ and 10 kPa negative pressure for 5 h, the surface residual pitch was cleaned with an ethanol solvent, and the sample was placed in a heating furnace and heated to 400 ℃ for 2 h to complete solidification. Finally, a ceramic and carbonaceous reinforcing carbon-based composite bipolar plate material was obtained.

[0068] Example 7

[0069] The embodiment provides a preparation method of a ceramic and carbonaceous reinforcing carbon-based composite bipolar plate material. The difference from the embodiment 2 is that no impregnation and solidification are performed, and other conditions are the same as those in the embodiment 2.

[0070] Example 8

[0071] The embodiment provides a preparation method of a ceramic and carbonaceous reinforcing carbon-based composite bipolar plate material. The difference from the embodiment 2 is that no pitch modifier (phenolic resin) is added, and other conditions are the same as those in the embodiment 2.

[0072] Example 9

[0073] The embodiment provides a preparation method of a ceramic and carbonaceous reinforcing carbon-based composite bipolar plate material. The difference from the embodiment 2 is that titanium boride is replaced by titanium carbide with the same mass, and other conditions are the same as those in the embodiment 2.

[0074] Comparative Example 1

[0075] The comparative example provides a preparation method of a bipolar plate material, which is different from example 2 in that a medium-temperature coal pitch and a pitch modifier (phenolic resin) are first used for heat polycondensation to generate a material containing pitch mesophase spherules, and then titanium boride, graphite and conductive graphite are uniformly mixed for subsequent hot pressing, sintering, carbonization and impregnation treatment, and other conditions are the same as those in example 2.

[0076] Comparative example 2

[0077] The comparative example provides a preparation method of a bipolar plate material, which is different from example 2 in that the reinforcing phase material (15 g of titanium boride with a particle size of 5 µm, 10 g of graphite with a particle size of 5 µm and 3 g of conductive carbon black) is replaced by a mixture of boron carbide and silicon powder (14 g of boron carbide and 14 g of silicon powder), and other conditions are the same as those in example 2.

[0078] Comparative example 3

[0079] The comparative example provides a preparation method of a bipolar plate material, which is different from example 2 in that, under the condition that the amount of the reinforcing phase raw material is the same, only titanium boride is used as the reinforcing phase, and other conditions are the same as those in example 2.

[0080] Comparative example 4

[0081] The comparative example provides a preparation method of a bipolar plate material, which is different from example 2 in that, under the condition that the amount of the reinforcing phase raw material is the same, only carbonaceous material (17.5 g of graphite and 10.5 g of conductive carbon black) is used as the reinforcing phase, and other conditions are the same as those in example 2.

[0082] Test example 1

[0083] The bipolar plate materials prepared in the above examples and comparative examples are tested for compressive strength, resistivity and corrosion current density, and the test results are shown in Tables 1-3. The compressive strength test method is as follows: after a standard test sample Φ 45 mm x 45 mm is prepared, the compressive strength test is carried out at a constant loading rate of 1 kN / s (the ultimate strain is the maximum strain value corresponding to the failure of the compressive strength, and the calculation formula is: ε = Δ L / L 0; wherein, ε is the ultimate strain, Δ L is the maximum compression amount before the material breaks, and L 0 is the original length of the material); the resistivity test method is as follows: the four-probe method is used for resistivity test (the standard test sample size is 50 mm x 50 mm x 4 mm); and the corrosion current density test method is as follows: a test sample (with a size of Φ12 mm x 4 mm) in 0.5 mol / L sulfuric acid solution with platinum plate as counter electrode at a scanning speed of 0.1 mV / s.

[0084] Table 1

[0085]

[0086] Table 2

[0087]

[0088] Table 3

[0089]

[0090] According to Tables 1-3, the compressive strength of the bipolar plate material prepared in Examples 1-9 is between 102.2 MPa and 145.3 MPa, the ultimate strain is between 5.9% and 7.1%, the resistivity is between 4.25 x 10 -6 Ω·m and 10.22 x 10 -6 Ω·m, and the corrosion current density is between 5.5 μA / cm 2 and 21.2 μA / cm 2 . The mechanical properties, electrical conductivity and corrosion resistance of the prepared bipolar plate material are excellent.

[0091] Compared with Examples 1-9, the compressive strength of the ceramic and carbon-based reinforced carbon composite bipolar plate material prepared in Comparative Example 1 by a non-in-situ coating method is only 88.6 MPa, and the resistivity is as high as 23.22 x 10 -6 Ω·m; the compressive strength of the carbon-based composite bipolar plate material prepared in Comparative Example 2 by using boron carbide and silicon powder as the reinforcing phase is relatively excellent, but the resistivity (as high as 80.41 x 10 -6 Ω·m) and the corrosion current density (as high as 55.2 μA / cm 2 ) are both high; the carbon-based composite bipolar plate material prepared in Comparative Example 3 only uses titanium boride as the reinforcing phase without adding a carbon-based reinforcing phase, and the electrical conductivity is poor (the resistivity is 44.21 x 10 -6 Ω·m); the carbon-based composite bipolar plate material prepared in Comparative Example 4 only uses a carbon-based material as the reinforcing phase without adding a ceramic reinforcing phase, and the mechanical properties, electrical conductivity and corrosion resistance are all poor (the compressive strength is only 89.5 MPa, the resistivity is as high as 26.37 x 10 -6 Ω·m, and the corrosion current density is as high as 64.7 μA / cm 2 ).

[0092] Compared with Example 2, the mechanical properties, electric conductivity and corrosion resistance of the carbon-based composite bipolar plate material prepared by not performing impregnation curing, not adding pitch modifier and replacing titanium boride with titanium carbide ceramic reinforcing phase in the same mass in Examples 7-9 are reduced to a certain extent, but the effect is still significantly better than that of the carbon-based composite bipolar plate material prepared in Comparative Examples 1-4.

[0093] Obviously, the above examples are only examples for clearly illustrating, but not limit the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and also impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for the production of ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, characterized in that The application relates to a ceramic-carbon composite bipolar plate material and a preparation method thereof. The ceramic-carbon composite bipolar plate material is prepared by mixing a ceramic reinforcing phase, a carbon reinforcing phase and a pitch compound as raw materials, performing a thermal polycondensation reaction, performing solvent extraction and solid-liquid separation to obtain a pitch mesophase carbon microsphere in-situ coated ceramic-carbon reinforcing phase precursor, performing hot-pressing to obtain a green body, performing sintering and carbonization treatment and impregnation treatment to obtain the ceramic-carbon composite bipolar plate material. The ceramic reinforcing phase comprises titanium boride. The pitch compound comprises at least one of coal pitch, petroleum pitch, naphthalene pitch and secondary refined pitch. The carbon reinforcing phase comprises at least one of graphite, expanded graphite, carbon black and carbon fiber.

2. The production method according to claim 1, characterized by, The particle size of the carbon reinforcing phase is 0.02-10 mu m. The particle size of the ceramic reinforcing phase is 0.1-10 mu m. The mass ratio of the pitch compound, the ceramic reinforcing phase and the carbon reinforcing phase is 20:(1-6):(0.1-3). The mixing process is performed at a temperature of 120-180 DEG C and a stirring speed of 1500-2500 r / min for 0.5-2 h. The temperature of the thermal polycondensation reaction is 380-420 DEG C.

3. The production method according to claim 1 or 2, characterized by, The heating rate of the thermal polycondensation reaction is 1-5 DEG C / min. The stirring speed of the thermal polycondensation reaction is 300-800 r / min. The time length of the thermal polycondensation reaction is 2-4 h. The thermal polycondensation reaction is performed in an inert atmosphere. The thermal polycondensation reaction is performed by additionally adding a pitch modifier. The thermal polycondensation reaction is performed by additionally adding a pitch modifier. The organic solvent used in the solvent extraction comprises at least one of tetrahydrofuran, toluene, pyridine, quinoline, dichloromethane, trichloroethylene and washed oil. The solid-liquid separation comprises at least one of filtration, sedimentation and centrifugation. The pitch modifier is a resin-based modifier. The mass ratio of the pitch modifier and the pitch compound is (0.5-4):

20.

4. The production method according to claim 3, characterized by, The molding temperature of the hot-pressing is 320-380 DEG C. The molding pressure of the hot-pressing is 30-80 MPa.

5. The production method according to claim 1 or 2, characterized by, The pressure maintaining time of the hot-pressing is 8-15 min. The hot-pressing is performed by additionally performing a sieving treatment. The sintering and carbonization treatment is performed by first increasing the temperature to 400-450 DEG C at a rate of 1-5 DEG C / min and maintaining the temperature for 1-2 h, and then continuously increasing the temperature to 900-1400 DEG C at a rate of 1-2 DEG C / min and maintaining the temperature for 2-5 h. The sintering and carbonization treatment is performed in an inert atmosphere.

6. The production method according to claim 1 or 2, characterized by, The impregnation agent used in the impregnation treatment is thermosetting phenolic resin or / and pitch. The impregnation treatment is performed under a negative pressure condition.

7. The production method according to claim 1 or 2, characterized by, The time length of the impregnation treatment is 5-10 h. The impregnation treatment is performed by additionally using an organic solvent for cleaning. The impregnation treatment is performed by additionally performing a solidification treatment. The negative pressure condition is 0.1-10 kPa. ​ 8. The preparation method according to claim 7, characterized in that, ​ And / or, the organic solvent comprises at least one of ethanol, acetone; And / or, when the impregnating agent is thermosetting phenolic resin, the temperature of the curing treatment is 160-190℃, and the time of the curing treatment is 1-2h; And / or, when the impregnating agent is asphalt, the asphalt quinoline insoluble content is not more than 0.1%, the softening point is 50-100℃, the temperature of the impregnating treatment is 100-120℃, the temperature of the curing treatment is 380-420℃, and the time of the curing treatment is 2-3h.

9. A ceramic and carbonaceous reinforced carbon-based composite bipolar plate material, characterized in that, The ceramic and carbonaceous reinforced carbon-based composite bipolar plate material is prepared by the method of any one of claims 1-8.

10. The use of the ceramic and carbonaceous reinforced carbon-based composite bipolar plate material of claim 9 in a fuel cell or a water electrolysis hydrogen production stack.

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