CN120109203A

CN120109203A - A cathode plate and its production process and application

Info

Publication number: CN120109203A
Application number: CN202510564350.9A
Authority: CN
Inventors: 李擎; 何进; 刘启; 李剑; 刘林湘
Original assignee: Hunan Qingcheng New Materials Technology Co ltd
Current assignee: Hunan Qingcheng New Materials Technology Co ltd
Priority date: 2025-04-30
Filing date: 2025-04-30
Publication date: 2025-06-06
Anticipated expiration: 2045-04-30
Also published as: CN120109203B

Abstract

The present invention provides a cathode plate and its production process and application, wherein the cathode plate comprises a fiber core layer, a titanium carbide doping layer, a titanium carbide and silicon carbide composite layer and a surface layer arranged in sequence from the inside to the outside. The present invention significantly improves the conductivity and mechanical strength of the cathode plate through the design of the titanium carbide doping layer and the titanium carbide and silicon carbide composite layer; at the same time, the design of the titanium carbide and silicon carbide composite layer further enhances the high temperature resistance and chemical stability of the material, so that the cathode plate can still maintain excellent performance in harsh environments such as high temperature, acid and alkali.

Description

Cathode plate and production process and application thereof

Technical Field

The application belongs to the technical field of electrode materials, and particularly relates to a cathode plate and a production process and application thereof.

Background

The cathode plate plays a critical role ‌ in the fuel cell. It is one of the key components in a fuel cell stack, and is usually used together with an anode plate to complete an electrochemical reaction. The cathode plate is primarily responsible for contact with an oxidant (e.g., oxygen) to produce electricity and water through a catalytic reaction. ‌ A

The traditional cathode plate is mostly made of stainless steel or titanium, and has the problems of poor conductivity, serious acid corrosion and the like. The current C/C composite cathode plate has advantages in the aspects of high temperature resistance, chemical stability, acid and alkali corrosion resistance and the like compared with the traditional copper cathode plate, but some places to be improved are found in operation, wherein the resistivity of the C/C composite cathode plate is generally 11-15 mu omega-m, relatively large resistance loss is generated in the current transmission process, more electric energy is converted into heat energy, the electric energy utilization efficiency is reduced, and the energy consumption cost is increased. While higher resistivity may affect the kinetics of the electrode reaction. In electrochemical processes such as electrolysis, the electric potential distribution on the surface of the electrode is uneven due to the electric resistance, so that the electrode reaction cannot be uniformly performed, the electrolysis efficiency is possibly reduced, and the consistency of the product quality is affected. Meanwhile, the electrode polarization phenomenon can be increased, and the efficiency and the energy utilization rate of the electrochemical process are further reduced. Accordingly, there is a need to provide a low resistance cathode plate.

Disclosure of Invention

The application provides a cathode plate, a production process and application thereof, and aims to solve the problem of high resistivity of the cathode plate to a certain extent.

The first aspect of the invention provides a cathode plate, which comprises a fiber core layer, a titanium carbide doped layer, a titanium carbide and silicon carbide composite layer and a surface layer which are sequentially arranged from inside to outside.

The second aspect of the invention provides a production process of a cathode plate, comprising the following steps:

1) Mixing the T800 fiber, the chopped fiber and the polyarylacetylene resin to form a fiber core layer;

2) After the fiber core layer is cured by hot pressing, introducing a carbon source, a titanium source, a silicon source and carrier gas for microwave pulse deposition, and respectively forming a titanium carbide doped layer, a titanium carbide and silicon carbide composite layer on the surface of the fiber core layer to obtain a deposited piece;

3) And (5) immersing the deposition piece, and carbonizing to obtain the cathode plate.

Further, the mass ratio of the T800 fiber to the chopped fiber to the polyarylacetylene resin is 50:10-20:25-40.

Further, the hot press solidification is that under the condition that the pressure is 0.3-0.8MPa, the temperature is raised to 80-90 ℃ by 1.5-2h, the temperature is kept for 10-20min, the temperature is raised to 150-160 ℃ by 2.5-3h, the temperature is kept for 10-20min, the temperature is raised to 210-230 ℃ by 1.5-2h, and the temperature is kept for 10-20min.

Further, the microwave pulse deposition includes a first deposition and a second deposition;

introducing a carbon source, a titanium source and a carrier gas in the first deposition process;

The temperature of the first deposition is 1100-1300 ℃, and the deposition time is 4-5h;

Introducing a carbon source, a silicon source, a titanium source and carrier gas in the process of the second deposition;

The temperature of the second deposition is 1000-1200 ℃ and the deposition time is 6-7h.

Further, the silicon source is used in an amount of 0.5% or less of the total mass of the sum of the carbon source, the titanium source and the carrier gas in the second deposition process.

Further, the microwave power of the microwave pulse deposition is 2.8-3.5kW.

Further, the pressure of the dipping treatment of the deposition part is 30-40 MPa, the temperature is 200-220 ℃ and the time is 4-5 h.

Further, the carbonization treatment comprises heating the immersed deposition piece to 640-660 ℃ at 1-3 ℃ per min under the protection of N ₂, and preserving heat for 2-3 hours to perform pre-carbonization treatment to obtain a pre-carbonized piece;

heating the pre-carbonized part to 1700-1850 ℃ at 8-10 ℃ per min under Ar atmosphere, and preserving heat for 3-4h to carry out graphitization treatment;

continuously heating to 2200-2300 ℃ in He atmosphere, preserving heat for 1-2h, and purifying at high temperature.

The present invention in its third aspect provides the use of a cathode plate in an electrode material.

The invention has the following beneficial effects:

(1) The cathode plate comprises a fiber core layer, a titanium carbide doped layer, a titanium carbide and silicon carbide composite layer and a surface layer which are sequentially arranged from inside to outside, wherein the design of the titanium carbide doped layer and the titanium carbide and silicon carbide composite layer obviously improves the conductivity and the mechanical strength of the cathode plate. Titanium carbide is used as a high-performance ceramic material, has excellent conductivity and high-temperature resistance, and can be doped between a fiber core layer and a surface layer, so that the resistivity can be effectively reduced, and the current transmission efficiency can be improved. Meanwhile, due to the design of the titanium carbide and silicon carbide composite layer, the high temperature resistance and chemical stability of the material are further enhanced, and the cathode plate can still maintain excellent performance in severe environments such as high temperature, acid and alkali.

(2) The production process adopts hot press solidification and microwave pulse deposition technology, and combines impregnation and carbonization treatment, thereby realizing the efficient preparation of the cathode plate. The uniformity and compactness of the fiber core layer are ensured in the hot press solidification process, and a good foundation is provided for subsequent microwave pulse deposition. The microwave pulse deposition technology has the advantages of high efficiency, uniformity, controllability and the like, and can realize the deposition and modification of materials in a short time. The impregnation and carbonization treatment further improves the density and uniformity of the material, ensuring the final performance of the cathode plate.

(3) The cathode plate has wide application prospect in electrode materials. The efficiency and stability of electrochemical devices such as fuel cells, electrolytic cells and the like can be remarkably improved due to the low resistivity, high conductivity and high temperature resistance.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a golden phase diagram provided in example 1;

FIG. 2 is a 500 XFEC scanning photograph of example 1;

FIG. 3 is a surface view of CVI provided in example 1;

fig. 4 is a polarization analysis chart of the CVI layer provided in example 1.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

In the present application, the term "and/or" describes an association relationship of an association object, which means that three relationships may exist, for example, a and/or B may mean that a exists alone, a and B exist together, and B exists alone. Wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the present specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that, in various embodiments of the present application, the sequence number of each process does not mean that the execution sequence is sequential, and some or all of the steps may be executed in parallel or sequentially, where the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

Unless otherwise specifically indicated, the various raw materials, reagents, instruments, equipment and the like used in the present application are commercially available or may be prepared by existing methods.

The technical scheme of the application is described below through specific examples and comparative examples.

An embodiment of the first aspect of the present invention provides a cathode plate, which includes a fiber core layer, a titanium carbide doped layer, a titanium carbide and silicon carbide composite layer, and a surface layer, which are sequentially disposed from inside to outside.

The design of the titanium carbide doped layer and the titanium carbide and silicon carbide composite layer obviously improves the conductivity and the mechanical strength of the cathode plate. Titanium carbide is used as a high-performance ceramic material, has excellent conductivity and high-temperature resistance, and can be doped between a fiber core layer and a surface layer, so that the resistivity can be effectively reduced, and the current transmission efficiency can be improved. Meanwhile, due to the design of the titanium carbide and silicon carbide composite layer, the high temperature resistance and chemical stability of the material are further enhanced, and the cathode plate can still maintain excellent performance in severe environments such as high temperature, acid and alkali.

An embodiment of the second aspect of the present invention provides a production process of a cathode plate, comprising the steps of:

The raw materials of the invention comprise T800 fibers, chopped fibers and polyarylacetylene resin, wherein the T800 fibers and the chopped fibers are used for synergistically reinforcing the matrix of the polyarylacetylene resin, so that the overall mechanical property and the electrical conductivity of the material are obviously improved. The production process adopts hot press solidification and microwave pulse deposition technology, and combines impregnation and carbonization treatment, thereby realizing the efficient preparation of the cathode plate. The uniformity and compactness of the fiber core layer are ensured in the hot press solidification process, and a good foundation is provided for subsequent microwave pulse deposition. The microwave pulse deposition technology has the advantages of high efficiency, uniformity, controllability and the like, and can realize the deposition and modification of materials in a short time. The dipping and carbonization treatment further improves the density and uniformity of the material, ensures the final performance of the cathode plate, obviously enhances the conductivity and high temperature resistance of the composite material, and ensures that the resistivity of the obtained cathode plate can reach 6.3 mu omega-m at the lowest, thereby meeting the application requirements of high-performance materials.

In an embodiment of the invention, the T800 fiber has a diameter of 7 μm, the chopped fiber has a diameter of 0.5 μm, and the chopped fiber has a length of 50-100. Mu.m. The T800 fiber has excellent tensile strength and elastic modulus, while the chopped fiber provides good dispersibility and interfacial bonding property, so that the mechanical property and the electrical conductivity of the composite material are obviously improved under the combined action. Further, the T800 fibers and chopped fibers were pre-treated prior to use. Wherein, the T800 carbon fiber is ultrasonically cleaned by acetone for 30 minutes, the frequency is 40kHz, the temperature is 80 ℃, and the surface sizing agent is removed. The chopped carbon fiber is ball milled at 300rpm for 2h to control the length of the chopped carbon fiber to 50-100 μm.

In an embodiment of the present invention, the mass ratio of the T800 fiber, the chopped fiber and the polyarylacetylene resin is 50:10-20:25-40. Preferably, the mass ratio of the T800 fiber to the chopped fiber to the polyarylacetylene resin is 50:15:35, and the mass ratio is verified by multiple tests, so that the optimal composite material performance can be obtained, and the quality and stability of the cathode plate are ensured.

In the embodiment of the invention, the hot pressing and curing are that the fiber core layer is poured into a graphite mold, the temperature is raised to 80-90 ℃ by 1.5-2h under the pressure of 0.3-0.8MPa, the temperature is kept for 10-20min, the temperature is raised to 150-160 ℃ by 2.5-3h, the temperature is kept for 10-20min, the temperature is raised to 210-230 ℃ by 1.5-2h, the temperature is kept for 10-20min, and the temperature is cooled to 60-70 ℃ after curing and is demoulded. Through the step heating and heat preservation process, the internal stress of the material is ensured to be released uniformly, the structural defect caused by temperature shock is avoided, and the durability and the reliability of the composite material are obviously improved.

In the embodiment of the invention, the microwave power of the microwave pulse deposition is 2.8-3.5kW, and the microwave pulse deposition comprises a first deposition and a second deposition;

Specifically, the microwave pulse deposition comprises the steps of introducing C ₃H₆、TiCl₄ and Ar into a microwave reactor at 800-900 ℃, heating to 1100-1300 ℃, depositing for 4-5 hours to generate a TiC doped layer, and preferably, depositing for 4 hours at the microwave power of 3.5kW, the temperature of 1200 ℃ and the pressure of 200 Pa. In the microwave pulse deposition process, the TiC doped layer is uniformly covered on the surface of the fiber core layer, so that the interface binding force is enhanced, the wear resistance and oxidation resistance of the material are effectively improved, and the service life of the cathode plate is further prolonged.

C ₃H₆、SiCl₄、TiCl₄ and Ar are then introduced into the microwave reactor, the temperature in the microwave reactor is controlled to be 1000-1200 ℃, and the deposition is carried out for 6-7 hours, so that the SiC-TiC composite layer is generated. Preferably, the microwave power is 2.8kW, the temperature is 1100 ℃, the pressure is 150Pa, and the deposition is carried out for 6 hours. The SiC-TiC composite layer uniformly covers the surface of the TiC doped layer, so that the surface hardness and corrosion resistance of the material are enhanced, and the overall performance of the cathode plate is further improved.

The silicon source is used in the second deposition process in an amount of 0.5% or less of the total mass of the sum of the carbon source, the titanium source and the carrier gas. The amount of SiCl ₄ is required to be limited to less than 0.5% of the total mass because excessive silicon sources introduce more defects and reduce the conductivity of the material. By precisely controlling the amount of SiCl ₄, a uniform distribution of silicon carbide in the composite layer can be ensured while maintaining excellent conductivity of the material. In addition, the microwave power of the microwave pulse deposition is controlled in the range of 2.8-3.5kW, and the power range can ensure the stability and the high efficiency of the deposition process and avoid the adverse effect of excessive or low power on the material performance.

After microwave pulse deposition, the microwaves are turned off, the temperature is reduced to 500 ℃ at 5 ℃ per minute under Ar atmosphere, the internal stress is eliminated, and the structural stability of the material is ensured.

In the embodiment of the invention, the impregnating pressure of the impregnating treatment of the deposition piece obtained in the step 2) is 30-40 MPa, the temperature is 200-220 ℃ and the time is 4-5 h.

Specifically, the deposition piece is subjected to dipping treatment, namely, mesophase pitch (with a softening point of 280 ℃ C.) is injected into the deposition piece to a volume of 60% under the condition that the vacuum degree is 1X 10 ^- Pa, CO ₂ is introduced to enable the dipping pressure to reach 30-40MPa, meanwhile, the temperature is raised to 200-220 ℃ and the pressure is maintained for dipping for 4-5 hours, the pressure is slowly released to normal pressure (the pressure release rate is 0.5 MPa/min), the sufficient permeation of the pitch is ensured, a compact protective layer is formed, the thermal shock resistance and the chemical stability of the material are enhanced, and finally, the long-term stable operation of the cathode plate under an extreme environment is realized.

In the embodiment of the invention, the carbonization treatment comprises heating a dipped deposition piece to 640-660 ℃ at 1-3 ℃ per min under the protection of N ₂ in a tube furnace, and preserving heat for 2-3 hours to perform pre-carbonization treatment to obtain a pre-carbonized piece;

transferring the pre-carbonized part to a high-temperature graphitization furnace, heating to 1700-1850 ℃ at 8-10 ℃ per min under Ar atmosphere, and preserving heat for 3-4h to perform graphitization treatment;

Continuously heating to 2200-2300 ℃ in He atmosphere, preserving heat for 1-2h, and purifying at high temperature to remove impurities and ensure the purity of the material.

Finally, through a plurality of fine processes, a compact and uniform composite protective layer is formed on the surface of the cathode plate, and the durability and reliability of the cathode plate in extreme environments such as high temperature, high pressure and the like are remarkably improved.

Embodiments of the third aspect of the invention provide the use of a cathode plate in an electrode material.

The cathode plate is particularly suitable for being used as an electrode material of electrochemical equipment such as fuel cells, electrolytic cells and the like due to the unique structure and excellent performance. The high conductivity and high temperature resistance ensure the high efficiency and stability of the electrochemical equipment in the running process.

Example 1

A production process of a low-resistance cathode plate comprises the following steps:

1) Mixing the T800 fiber, the chopped fiber and the polyarylacetylene resin in a ratio of 50:15:35, and stirring to form uniform slurry;

2) Injecting the fiber core layer into a graphite mold, heating to 80 ℃ for 2 hours under the condition of 0.5MPa, preserving heat for 10min, heating to 150 ℃ for 2.5 hours, preserving heat for 10min, heating to 220 ℃ for 1.5 hours, preserving heat for 10min, cooling to 60 ℃ after solidification, and demolding;

3) Introducing C ₃H₆、TiCl₄ and Ar into a microwave reactor at 800 ℃, heating to 1200 ℃, depositing for 4 hours at a microwave power of 3.5kW to generate a TiC doped layer, introducing C ₃H₆、SiCl₄, tiCl ₄ and Ar into the microwave reactor, controlling the temperature in the microwave reactor to be 1100 ℃, depositing for 6 hours at a microwave power of 2.8kW to generate a SiC-TiC composite layer, and obtaining a deposited piece;

4) Dipping the deposited piece, namely injecting mesophase pitch into the deposited piece under the condition that the vacuum degree is 1 multiplied by 10 ^- Pa, introducing CO ₂ to raise the vacuum degree to 35MPa, raising the temperature to 200 ℃ at the same time, and maintaining the pressure for dipping for 4 hours;

5) Heating the immersed deposition piece to 650 ℃ at 2 ℃ per min under the protection of N ₂, preserving heat for 2 hours to obtain a pre-carbonized piece, heating the pre-carbonized piece to 1800 ℃ at 9 ℃ per min under the Ar atmosphere, preserving heat for 3 hours to carry out graphitization treatment, continuously heating to 2200 ℃ under the He atmosphere, preserving heat for 1 hour to carry out high-temperature purification, and obtaining the low-resistance cathode plate.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 6.3. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 165MPa.

The golden phase diagram of the low-resistance cathode plate in the embodiment is shown in fig. 1, and the golden phase diagram shows that the microstructure is uniform and compact and the porosity is low.

Fig. 2 is a 500-fold field emission electron microscope scanning photograph of the low resistance cathode plate of the present embodiment.

The CVI surface diagram is shown in fig. 3, and shows that the surface of the material has good uniformity and no obvious cracks and holes, and fine grain structures can be clearly identified, and the grains are closely arranged, so that the excellent compactness of the material is shown.

The polarization analysis of the CVI layer is shown in fig. 4, and the polarization diagram shows that the internal stress in the CVI layer is uniformly distributed, and no obvious stress concentration area exists, so that the high stability of the material is further proved.

The process is authenticated by an ISO 9001 quality management system, the annual production capacity of a single line can reach 5000 tablets, and the product percent of pass is 98.5%.

Example 2

A low resistance cathode plate was prepared using the process of example 1 except that the T800 fibers, chopped fibers, and polyarylacetylene resin were mixed in a ratio of 50:20:30.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 8.5. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 143MPa.

The reason for the lower flexural strength of example 2 than example 1 is that the chopped fiber content is increased, while the dispersibility and interfacial adhesion properties of the material are enhanced, while the compactness of the overall fiber structure is also slightly reduced, so that the flexural strength of the material is reduced when subjected to flexural loads.

Example 3

A low resistance cathode plate was prepared using the procedure of example 1 except that the T800 fibers, chopped fibers, and polyarylacetylene resin were mixed in a ratio of 50:12:38.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 7.5. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 124MPa.

The reason for the lower flexural strength of example 3 than example 1 is that the increased content of the polyarylene acetylene resin, while improving the overall adhesion and processability of the material, relatively reduced content of fibers, results in reduced mechanical support of the material, and thus exhibits lower flexural strength in flexural testing.

Example 4

The process of example 1 was used to prepare a low resistance cathode plate, except that the fibrous core layer was injected into a graphite mold, heated to 90 ℃ over 2 hours under a pressure of 0.6MPa, incubated for 20min, then heated to 160 ℃ over 3 hours, incubated for 20min, then heated to 230 ℃ over 2 hours, and incubated for 20min.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 7.1. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 158MPa.

Example 4 the process time and temperature of the thermal press curing of the fiber core layer were adjusted to a small extent, and the flexural strength was closer to that of example 1.

Example 5

The process of example 1 was used to prepare a low resistance cathode plate, except that C ₃H₆、TiCl₄ and Ar were introduced into a microwave reactor at 900℃and heated to 1300℃with a microwave power of 3.5kW for 5h to produce a TiC doped layer, and then C ₃H₆、SiCl₄ and TiCl ₄ and Ar were introduced into the microwave reactor to control the temperature in the microwave reactor to 1200℃with a microwave power of 2.8kW and for 7h to produce a SiC-TiC composite layer, to obtain a deposited article.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 9.6. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 117MPa.

Example 5 the reason for the lower flexural strength is that the microwave pulse deposition time is prolonged, while enhancing the thickness and uniformity of the composite to some extent, the excessive deposition time also results in an accumulation of internal stress in the material, resulting in a decrease in flexural strength of the material in flexural testing, as opposed to example 1.

Example 6

The process of example 1 was used to prepare a low-resistance cathode plate, except that the immersed deposition was heated to 660 ℃ at 3 ℃ per minute under the protection of N ₂, heat-preserved for 3 hours to perform pre-carbonization to obtain a pre-carbonized piece, the pre-carbonized piece was heated to 1850 ℃ at 10 ℃ per minute under Ar atmosphere to perform graphitization for 4 hours, and the temperature was continuously raised to 2300 ℃ under He atmosphere, heat-preserved for 2 hours to perform high-temperature purification to obtain a low-resistance cathode plate.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 10.2. Mu. OMEGA.m. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 106MPa.

Example 6 is in contrast to example 1, and the reason for the lower flexural strength may be that the temperature and time control of the pre-carbonization, graphitization and high temperature purification during the carbonization process is more stringent, and while such process conditions can further improve the purity and structural stability of the material, the brittleness of the material is relatively increased, resulting in a decrease in flexural strength of the material in the flexural test.

Comparative example 1

The process of example 1 was used to prepare a low resistance cathode plate except that the T800 fibers, chopped fibers and polyarylacetylene resins were replaced with graphite powder, phenolic resin, chopped fibers.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 16.4. Mu. OMEGA.m. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 89MPa.

This result shows that the combination of T800 fibers, chopped fibers and polyarylacetylene resin can significantly reduce the resistivity of the cathode plate and increase the bending strength compared to the conventional combination of graphite powder, phenolic resin and chopped fibers. The high strength and modulus of the T800 fibers, together with the excellent thermal stability and chemical inertness of the polyarylacetylene resin, gives the cathode plate excellent mechanical properties and weatherability. In addition, the addition of chopped fibers further enhances the toughness and impact resistance of the material so that the cathode plate remains stable and durable in extreme environments.

Comparative example 2

The process of example 1 was used to prepare a low resistance cathode plate, except that the microwave pulse deposition process was eliminated.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 23.6. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 68MPa.

This result shows that the lack of the microwave pulse deposition process results in uneven internal structure of the material, increased resistivity and reduced bending strength, and it is seen that the microwave pulse deposition process has an important effect on the performance of the cathode plate.

Comparative example 3

The process of example 1 was used to prepare a low resistance cathode plate except that no mesophase pitch impregnation treatment was used.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 18.7. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 76MPa.

The result shows that the intermediate phase asphalt dipping treatment can obviously improve the uniformity of the internal structure of the cathode plate, and the reason is probably that the intermediate phase asphalt can permeate into the micro pores of the material to form a continuous protective layer, so that the corrosion of the external environment is effectively prevented, and meanwhile, the binding force in the material is enhanced, thereby improving the overall mechanical property and electrical property.

Comparative example 4

The process of example 1 was used to prepare a low resistance cathode plate, except that the pre-carbide was graphitized by adjusting the rate of temperature rise in an Ar atmosphere to 5℃per minute and maintaining the temperature for 5 hours.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 9.8. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 112MPa.

This result shows that too slow a heating rate and too long a holding time can result in insufficient graphitization treatment, affect the graphitization degree of the material, further increase the resistivity and reduce the flexural strength.

Comparative example 5

The process of example 1 was used to prepare a low resistance cathode plate except that the silicon source was used in an amount of 10% of the total mass of carbon source, titanium source and carrier gas during the second deposition.

The volume resistivity was measured using a four-point probe method, and the resistance of the low-resistance cathode plate prepared under the conditions of this example was 17.5. Mu. Ω. M. A universal tester is adopted to carry out three-point bending test, the span is 100mm, the loading rate is 1mm/min, and the bending strength is 84MPa.

This result shows that excessive silicon source usage may result in excessive SiC content in the SiC-TiC composite layer, which breaks the balance between TiC and SiC, resulting in an increase in resistivity and a decrease in flexural strength of the material. In addition, excessive silicon sources may also cause maldistribution of internal stress in the material, affecting its long-term stability.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference may be made to related descriptions of other embodiments.

The foregoing embodiments are merely illustrative of the technical solutions of the present application, and not restrictive, and although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that modifications may still be made to the technical solutions described in the foregoing embodiments or equivalent substitutions of some technical features thereof, and that such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. The cathode plate is characterized by comprising a fiber core layer, a titanium carbide doped layer, a titanium carbide and silicon carbide composite layer and a surface layer which are sequentially arranged from inside to outside.

2. The production process of the cathode plate is characterized by comprising the following steps of:

3. The process for producing a cathode plate according to claim 2, wherein the mass ratio of the T800 fibers, the chopped fibers and the polyarylacetylene resin is 50:10 to 20:25 to 40.

4. The process for producing a cathode plate according to claim 2, wherein the hot press curing is performed under a pressure of 0.3 to 0.8MPa, by heating to 80 to 90 ℃ for 1.5 to 2 hours, maintaining the temperature for 10 to 20 minutes, heating to 150 to 160 ℃ for 2.5 to 3 hours, maintaining the temperature for 10 to 20 minutes, heating to 210 to 230 ℃ for 1.5 to 2 hours, and maintaining the temperature for 10 to 20 minutes.

5. The process for producing a cathode plate according to claim 2, wherein the microwave pulse deposition includes a first deposition and a second deposition;

6. The process according to claim 5, wherein the amount of the silicon source used in the second deposition process is 0.5% or less of the total mass of the sum of the carbon source, the titanium source and the carrier gas.

7. The process for producing a cathode plate according to claim 5, wherein the microwave power of the microwave pulse deposition is 2.8-3.5kW.

8. The process for producing a cathode plate according to claim 2, wherein the dipping pressure of the dipping treatment of the deposited piece is 30-40 mpa, the temperature is 200-220 ℃ and the time is 4-5 hours.

9. The process for producing a cathode plate according to claim 2, wherein the carbonization treatment comprises heating the immersed deposition member to 640-660 ℃ at 1-3 ℃ per min under the protection of N ₂, and preserving heat for 2-3 hours to perform pre-carbonization treatment to obtain a pre-carbonized member;

and continuously heating to 2200-2300 ℃ in the He atmosphere, and preserving the temperature for 1-2h for purification.

10. Use of a cathode plate according to claim 1 or a cathode plate obtained by a process for the production of a cathode plate according to any one of claims 2 to 9 in an electrode material.