High-performance epoxy carbon-based high-temperature-resistant acid-resistant anticorrosive filling material and preparation method thereof

Abstract

This invention discloses a method for preparing a high-performance epoxy carbon-based high-temperature and acid-resistant corrosion-resistant filler: 1. Raw material preparation and pretreatment; 2. Mixing a dual-modified conductive filler with a titanate hydrate solution, followed by high-speed shearing and vacuum extraction to obtain conductive material powder; 3. Preparing filler component A; 4. Preparing filler component B; 5. Mixing filler components A and B and coating them onto the surface of a carbon material, performing pre-curing and step-by-step gradient curing for shaping, and cooling to room temperature to obtain the target filler material. This invention also discloses the prepared high-performance epoxy carbon-based high-temperature and acid-resistant corrosion-resistant filler. The method for preparing this high-performance epoxy carbon-based high-temperature and acid-resistant corrosion-resistant filler provided by this invention, through a process of "synergistic modification of multi-component carbon-based fillers + modification of epoxy resin matrix + step-by-step gradient curing," improves the interfacial compatibility between the filler material and the carbon material, and enhances the high-temperature resistance, acid corrosion resistance, and mechanical bonding properties of the filler material.

Description

Technical Field

[0001] This invention belongs to the field of engineering material preparation technology, specifically relating to a method for preparing high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler materials, and also relating to high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler materials prepared using the above preparation method. Background Technology

[0002] In practical engineering scenarios such as the assembly of flow battery stacks (e.g., vanadium redox flow batteries, lead redox flow batteries) and the connection of carbon fiber composite components, the interfacial connection between carbon fibers (including carbon fiber conductive plates, carbon nanotube-carbon fiber composite electrodes, etc.) and metal current collectors or dissimilar materials must simultaneously meet multiple core performance requirements: on the one hand, it must have excellent conductivity to reduce interfacial contact resistance and ensure overall conductivity efficiency; on the other hand, it must be able to resist the failure risks such as interface separation and performance degradation caused by harsh conditions such as acid corrosion and temperature fluctuations, to ensure the long-term stability of the structure.

[0003] Carbon powder itself has a graphite-like crystal structure and a carbon content typically exceeding 95%. It possesses excellent chemical inertness and high-temperature resistance. However, due to its strong surface inertness and low number of active groups, its interfacial compatibility is poor. Traditional filler materials struggle to form a stable interfacial bond with it, and it is prone to interfacial separation and decreased conductivity in harsh environments such as acid / alkali conditions and high / low temperature cycling. Existing commercial filler materials often use silver or copper powder as conductive fillers. While these achieve excellent conductivity, these metal fillers have poor acid corrosion resistance and are susceptible to electrochemical corrosion in acidic environments, leading to material failure. Using graphite powder as a single conductive filler can improve corrosion resistance to some extent, but the high-temperature resistance, wet aging resistance, and mechanical bonding properties of the filler material are significantly insufficient, failing to meet the practical application requirements of carbon materials in harsh environments such as flow batteries and marine engineering.

[0004] To address the core technical challenges of toner interface bonding and protection, there is an urgent need to develop a specialized filler material that combines high conductivity, high bonding strength, excellent high temperature resistance, and acid corrosion resistance to achieve long-term stable bonding between carbon materials and other components, meeting the service requirements under harsh environments. Summary of the Invention

[0005] The first objective of this invention is to provide a method for preparing high-performance epoxy carbon-based high-temperature and acid-resistant anti-corrosion filler materials. By constructing an innovative system of "synergistic modification of multi-element carbon-based fillers + modification of epoxy resin matrix + stepwise gradient curing", the interfacial compatibility between the filler material and carbon material is significantly improved. At the same time, the high-temperature resistance, acid corrosion resistance and mechanical bonding properties of the filler material are enhanced, solving the problems of poor compatibility, short service life and imperfect preparation process of existing filler materials.

[0006] The second objective of this invention is to provide a high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material prepared using the above-described preparation method.

[0007] The first technical solution adopted in this invention is: The preparation method of high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material is as follows: S1. Raw material preparation and pretreatment: Prepare titanate hydrate solution, modified epoxy resin and double-modified conductive filler respectively; S2. The double-modified conductive filler is mixed with a titanate hydrate solution, sheared at high speed, spread and then vacuum extracted to obtain conductive material powder. S3. The conductive material powder is mixed with the modified epoxy resin, and then sheared and ultrasonically dispersed to obtain the filler component A. S4. The crosslinking agent and catalyst are magnetically mixed, and an antioxidant is added to obtain the filler material component B. S5. Mix the filler component A and filler component B and apply them to the surface of the carbon material. Perform pre-curing and step-by-step gradient curing and shaping. Cool to room temperature to obtain the target filler material.

[0008] The invention is further characterized by: The specific method for preparing the titanate hydrate solution in S1 is as follows: A uniformly dispersed titanate hydrated solution is obtained by mixing titanate ester with deionized water at a mass ratio of 2~2.5:400~450 and stirring magnetically at a temperature of 45℃~55℃ for 10min~15min. The titanate is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester in a mass ratio of 1:0.5~1. The CAS number of triisostearoyl titanate is 61417-49-0, and the CAS number of bis(ethyl acetoacetate) titanate diisopropyl ester is 27858-32-8.

[0009] The specific preparation method of the modified epoxy resin in S1 is as follows: The modified epoxy resin can be obtained by mixing the diluent, epoxy resin and silane coupling agent and stirring at a constant temperature of 60℃~70℃ for 15min~20min. The mass ratio of diluent to epoxy resin is 200~220:75~80, and the mass ratio of diluent to silane coupling agent is 200~220:1.5~2.5. The diluent is isopropanol; The epoxy resin is a bisphenol A type epoxy resin; The silane coupling agent is γ-aminopropyltriethoxysilane.

[0010] The specific preparation method of the dual-modified conductive filler in S1 is as follows: Flake graphite, conductive carbon black and carbon nanofibers were stirred and mixed to obtain a multi-component mixed conductive filler. The multi-component mixed conductive filler was placed in an argon atmosphere and subjected to plasma treatment at a power of 300W~350W for 8min~12min. Then, the plasma-treated multi-component mixed conductive filler was added to a titanate hydrate solution and modified by constant temperature stirring at 45℃~55℃ for 20min~30min to obtain a double-modified conductive filler. The mass ratio of flake graphite to conductive carbon black is 100:5~6, and the mass ratio of flake graphite to carbon nanofiber is 100:3~4. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 108~113:402~452.5; The particle size of flake graphite is 100-200 mesh, the particle size of conductive carbon black is 30-40 nm, and the diameter of carbon nanofiber is 50-80 nm and the length of carbon nanofiber is 5-10 μm. During plasma treatment, the argon flow rate is 20~30 sccm.

[0011] The specific method for S2 is as follows: The dual-modified conductive filler and titanate hydrate solution were mixed at a mass ratio of 108~113:402~452.5. The mixture was first sheared at a shear rate of 2500r / min~3000r / min for 20min~30min to obtain a mixed slurry. The mixed slurry was then spread into a thin layer with a thickness of 2.5mm~2.9mm and vacuum extracted at 80℃~120℃ for 1h~3h to obtain conductive material powder.

[0012] The specific method for S3 is as follows: Conductive material powder and modified epoxy resin are mixed at a mass ratio of 510~565.5:276.5~302.5. The mixture is first sheared at a shear rate of 2500r / min~3000r / min for 20min~30min, and then ultrasonically dispersed at a power of 200W~250W and a frequency of 40kHz for 10min~15min to obtain the filler component A.

[0013] The specific method for S4 is as follows: The crosslinking agent and catalyst are mixed at a mass ratio of 62~65:0.8~0.9 and magnetically stirred at room temperature for 10min~15min to ensure thorough mixing. Then, antioxidant 1010 is added at a mass ratio of 0.3%~0.5% of the crosslinking agent, and stirring is continued for 5min~10min to obtain component B of the filler material. The crosslinking agent is a mixture of adipic acid and sebacic acid in a mass ratio of 3:1. The catalyst was obtained by compounding benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1.

[0014] The specific method for S5 is as follows: Mix filler component A and filler component B thoroughly at a mass ratio of 786.5~868:62.8~65.9, then apply the mixture to the surface of the carbon material. Use a stepwise gradient curing process: first pre-cur at 80℃~90℃ for 30min~40min, then cure at 120℃~130℃ for 1.5~2h, and finally cure at 150℃~160℃ for 30min. Cool to room temperature to obtain a high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material.

[0015] The second technical solution adopted in this invention is: The high-performance epoxy carbon-based high-temperature resistant, acid-resistant and corrosion-resistant filler material prepared according to the above preparation method has an electrical conductivity ≥18S / cm and an interfacial shear strength with carbon fiber material ≥40MPa. High-performance epoxy carbon-based high-temperature and acid-resistant anti-corrosion filler material, after being immersed in 65% sulfuric acid solution for 12 months, exhibits an interfacial shear strength greater than 15 MPa and an electrochemical corrosion rate of <5 μA / cm². High-performance epoxy carbon-based high-temperature and acid-resistant anti-corrosion filler material has a performance degradation rate of <5% within 3000 hours when used in an environment of 150℃.

[0016] The beneficial effects of this invention are: (1) The preparation method of the high-performance epoxy carbon-based high temperature and acid corrosion resistant filler material of the present invention realizes the innovation of the filler system: adopting a multi-component combination of flake graphite (main conductive phase), conductive carbon black (auxiliary conductivity, constructing conductive network) and carbon nanoparticles (strengthening conductive channels and improving mechanical properties), combined with plasma + titanate dual modification process, not only solves the problem of uneven conductivity and mechanical properties of single filler, but also significantly improves the compatibility of filler with epoxy resin matrix and carbon nanoparticle surface; (2) The preparation method of the high-performance epoxy carbon-based high temperature and acid resistant anti-corrosion filler material of the present invention realizes the innovation of preparation process: the addition of modified epoxy resin preparation (silane coupling agent modification), ultrasonic dispersion assistance, stepwise gradient curing and antioxidant addition processes solve the problems of filler agglomeration, large internal stress during curing and poor aging resistance in the existing preparation process; the stepwise gradient curing process can effectively reduce microcracks at the bonding interface, improve the interfacial bonding strength with carbon powder, and adapt to the porous and inert surface characteristics of carbon fiber powder; (3) The preparation method of the high-performance epoxy carbon-based high temperature and acid resistant anti-corrosion filler material of the present invention realizes the innovation of component compounding: the titanate, crosslinking agent and catalyst are all compounded systems, rather than single components, which can synergistically improve the modification effect, curing stability and reaction rate of the filler material, adapt to the special requirements of carbon powder bonding, and break through the performance limitations of existing single components. (4) The high-performance epoxy carbon-based high-temperature and acid-resistant anti-corrosion filler material prepared by the present invention has significant performance advantages: the electrical conductivity of the filler material is ≥18S / cm, the interfacial shear strength with carbon fiber powder is increased to more than 40MPa, and there is no separation phenomenon in the temperature cycle of -60℃~120℃; after soaking in 65% sulfuric acid solution for 12 months, the interfacial shear strength is still greater than 15MPa, and the electrochemical corrosion rate is <5μA / cm²; it can be used for a long time in an environment of 150℃, which is significantly better than the high temperature and acid corrosion resistance of existing filler materials, and is suitable for the application of carbon fiber powder in harsh environments; (5) The high-performance epoxy carbon-based high-temperature and acid-resistant anti-corrosion filler material prepared by the present invention has strong adaptability and wide application: it is specially designed for the surface inertness and porous characteristics of carbon materials, and can be perfectly adapted to the filling of carbon fiber-based components such as carbon material conductive plates and carbon nanotube-carbon fiber composite electrodes with metal current collectors. It can not only solve the encapsulation technology problem of carbon fiber components in flow batteries, but also be applied to the filling and connection of carbon material structural components in marine engineering and high-temperature acid conditions. It has good industrialization prospects and fills the market gap of special high-temperature and acid-resistant filler materials for carbon materials. Detailed Implementation

[0017] The present invention will now be described in detail with reference to specific embodiments.

[0018] The present invention discloses a method for preparing a high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material, the specific method of which is as follows: S1. Raw material preparation and pretreatment: Prepare titanate hydrate solution, modified epoxy resin and double-modified conductive filler respectively; The specific method for preparing the titanate hydrate solution is as follows: A uniformly dispersed titanate hydrated solution is obtained by mixing titanate ester with deionized water at a mass ratio of 2~2.5:400~450 and stirring magnetically at a temperature of 45℃~55℃ for 10min~15min. The titanate is composed of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester in a mass ratio of 1:0.5~1. The CAS number of triisostearoyl titanate is 61417-49-0, and the CAS number of bis(ethyl acetoacetate) titanate diisopropyl ester is 27858-32-8.

[0019] This invention employs the synergistic effect of two titanate esters, which can improve the bonding strength between the filler and the matrix and enhance the dispersion uniformity of the conductive filler, significantly outperforming the modification effect of a single titanate ester.

[0020] Titanate hydrate solution: Titanate is a water-soluble monoalkyl pyrophosphate ester, which can improve the bonding force between conductive filler and epoxy resin, and also improve the dispersion of conductive filler in the matrix, which helps to improve the conductivity and uniformity of the filler material. When diluted with deionized water at a certain temperature, the titanate coupling agent is fully and uniformly dispersed in it. The high-speed shear machine provides interlayer shear force to disperse the nanoparticles, thereby achieving surface modification of the conductive filler.

[0021] Furthermore, the specific preparation method of the modified epoxy resin is as follows: The modified epoxy resin can be obtained by mixing the diluent, epoxy resin and silane coupling agent and stirring at a constant temperature of 60℃~70℃ for 15min~20min. The mass ratio of diluent to epoxy resin is 200~220:75~80, and the mass ratio of diluent to silane coupling agent is 200~220:1.5~2.5. In this invention, the diluent is isopropanol, which mainly reduces the viscosity of the epoxy resin and improves the dispersion of the conductive filler in the resin; the epoxy resin is bisphenol A type epoxy resin, which is a thermosetting resin with good bonding strength and chemical resistance, preferably with a molecular weight of 300-700 and a softening point of less than 30°C; the silane coupling agent is γ-aminopropyltriethoxysilane.

[0022] This invention grafts epoxy resin with a silane coupling agent, introducing active groups onto the epoxy resin molecular chain. This significantly improves the compatibility of the epoxy resin matrix with the doubly modified conductive filler and toner surface, while also optimizing the flowability of the epoxy resin. This solves the problems of high viscosity and weak bonding between traditional epoxy resin and toner. This modification scheme is specifically adapted to the surface characteristics of toner, laying the foundation for subsequent improvement of interfacial bonding strength.

[0023] Furthermore, the specific preparation method of the dual-modified conductive filler is as follows: Flake graphite, conductive carbon black, and carbon nanofibers are stirred and mixed to obtain a multi-component mixed conductive filler. The multi-component mixed conductive filler is placed in an argon atmosphere with an argon flow rate of 20-30 sccm (this invention precisely controls the argon flow rate to ensure sufficient activation of the filler surface, while avoiding over-treatment that could damage the filler structure, improving the bonding effect with the titanate hydrate solution, and thus enhancing the interfacial compatibility with carbon powder). Plasma treatment is performed at a power of 300W-350W for 8-12 minutes to efficiently remove impurities, oil stains, and inert layers from the filler surface, while introducing active functional groups (hydroxyl and carboxyl groups) to the filler surface to achieve surface activation. The plasma-treated multi-component mixed conductive filler is then added to the titanate hydrate solution and modified by constant stirring at 45℃-55℃ for 20-30 minutes to obtain a double-modified conductive filler. The mass ratio of flake graphite to conductive carbon black is 100:5~6, and the mass ratio of flake graphite to carbon nanofiber is 100:3~4. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 108~113:402~452.5; Flake graphite has a particle size of 100-200 mesh, exhibits a micron-scale layered structure, contains 99.97% carbon, and has a bulk electrical conductivity greater than 1×10⁻⁶. 3 S / cm, as the main conductive material for the filler; The conductive carbon black is acetylene black, a black fine powder with a spherical nanoparticle structure, a particle size of 30nm~40nm, and a carbon content of 99.5%. The conductivity of the conductive carbon black is approximately 1×10⁻⁶. 3 S / cm, as an auxiliary conductive filler, can increase the conductive channels between flake graphite powders and improve the conductivity of the filler material; The diameter of the carbon nanofibers is 50nm~80nm and the length is 5μm~10μm. The addition of carbon nanopowder and the specific ratio of the three are one of the core innovations. By compounding the three in proportion and performing double modification, the three work together to achieve a balanced improvement in electrical conductivity and mechanical properties.

[0024] This invention further enhances the compatibility between fillers and epoxy resin matrices through the bridging effect of titanate coupling agents, while simultaneously improving the dispersion stability of fillers in the matrix, thus achieving dual modification. This dual modification process (plasma activation + titanate grafting) is an original design of this invention and has not yet been applied in toner-specific filler materials, effectively solving the problems of poor single modification effect and poor compatibility between fillers and matrix.

[0025] S2. The double-modified conductive filler is mixed with a titanate hydrate solution, subjected to high-speed shearing, spread, and then vacuum extracted to obtain conductive material powder; the specific method is as follows: The dual-modified conductive filler and titanate hydrate solution were mixed at a mass ratio of 108~113:402~452.5. The mixture was first sheared at a shear rate of 2500r / min~3000r / min for 20min~30min to obtain a mixed slurry. The shear force was used to break up the filler agglomerates, so that the conductive filler was uniformly dispersed in the titanate hydrate solution to obtain a homogeneous mixed slurry. The mixed slurry was then spread to a thickness of 2.5mm~2.9mm (the optimized precise thickness to avoid incomplete dehydration due to excessive thickness or affecting the powder yield due to excessive thinness). The mixture was then vacuum extracted at 80℃~120℃ for 1h~3h to completely remove the moisture from the slurry, and the conductive material powder was obtained.

[0026] This process solves the problems of incomplete dehydration and filler agglomeration in traditional powder preparation, and is also suitable for subsequent coating requirements.

[0027] S3. The conductive material powder is mixed with the modified epoxy resin, and then dispersed by high-speed shearing and ultrasonication to obtain the filler component A; the specific method is as follows: Conductive material powder and modified epoxy resin were mixed at a mass ratio of 510~565.5:276.5~302.5. The mixture was first sheared at a shear rate of 2500r / min~3000r / min for 20min~30min to initially achieve mixing between the powder and the matrix. Then, the mixture was placed in an ultrasonic disperser and ultrasonically dispersed at a power of 200W~250W and a frequency of 40kHz for 10min~15min. The cavitation effect of ultrasound was used to further break up the micro-agglomerates, so that the conductive material powder was fully and uniformly dispersed in the modified epoxy resin without any agglomeration, thus obtaining the filler component A.

[0028] The purpose of selecting an ultrasonic frequency of 40kHz is to avoid high-frequency dispersion from damaging the structure of the conductive filler, while ensuring uniform dispersion. This invention employs a unique dual dispersion process combining ultrasonic dispersion and high-speed shearing, which solves the industry pain point of uneven filler dispersion in existing technologies and ensures the conductivity uniformity and mechanical stability of the filler material.

[0029] S4. Magnetically mix the crosslinking agent and catalyst, add the antioxidant, and obtain component B of the filler material; the specific method is as follows: The crosslinking agent and catalyst are magnetically stirred at room temperature for 10-15 minutes at a mass ratio of 62-65:0.8-0.9 to ensure thorough mixing. Then, antioxidant 1010 is added at 0.3-0.5% of the mass of the crosslinking agent, and stirring is continued for 5-10 minutes to obtain component B of the filler material. The crosslinking agent is a mixture of adipic acid and sebacic acid in a mass ratio of 3:1. Adipic acid is an organic dicarboxylic acid. Organic functional carboxylic acids can undergo esterification with epoxy groups in epoxy resin to generate macromolecules with a network structure. Compared with a single adipic acid crosslinking agent, it can significantly improve the curing stability and mechanical strength of the filler material, while reducing the curing shrinkage rate.

[0030] The catalyst is a mixture of benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1. Benzyl dimethylamine is an organic tertiary amine that can catalyze the crosslinking agent oxalic acid to provide negative ion active centers, promoting the anionic polymerization reaction between epoxy resin and the crosslinking agent. The combination of these two catalysts allows for precise control of the curing rate, avoiding excessively rapid curing that generates internal stress and excessively slow curing that affects production efficiency. This ensures precise and controllable curing process, making it suitable for the curing requirements of porous carbon material surfaces.

[0031] This invention, by adding antioxidant 1010, can effectively inhibit the oxidative aging of filler materials under high temperature and acidic environments, significantly improve the long-term service life of filler materials, and solve the problem of poor aging resistance of existing filler materials.

[0032] S5. Mix filler component A and filler component B, apply the mixture to the surface of the carbon material, perform pre-curing and step-by-step gradient curing for shaping, and cool to room temperature to obtain the target filler material. The specific method is as follows: Filler component A and filler component B are thoroughly mixed at a mass ratio of 786.5~868:62.8~65.9, and then applied to the surface of carbon material (precisely matching the inert and porous characteristics of the carbon material surface to ensure full contact and penetration between the filler layer and the carbon fiber material surface). A step-by-step gradient curing process is adopted. First, pre-curing is carried out at 80℃~90℃ for 30~40 minutes to initially fix the filler layer and remove air bubbles in the filler layer; then curing is carried out at 120℃~130℃ for 1.5~2 hours to achieve full cross-linking of the filler layer; finally, curing is carried out at 150℃~160℃ for 30 minutes to eliminate curing internal stress and further improve the interfacial bonding strength between the filler layer and carbon powder. After cooling to room temperature, the high-temperature resistant, acid-resistant, and corrosion-resistant filler material is obtained.

[0033] This stepwise gradient curing process breaks through the limitations of traditional single-temperature curing, effectively reducing microcracks at the bonding interface, improving connection stability, and precisely adapting to the thermal expansion characteristics of the toner, thus avoiding interface separation caused by thermal stress during the curing process.

[0034] The high-temperature resistant and acid-resistant anti-corrosion filler material prepared according to the preparation method of the present invention has an electrical conductivity ≥18S / cm and an interfacial shear strength with carbon fiber material ≥40MPa. After being immersed in 65% sulfuric acid solution for 12 months, the high-temperature resistant and acid-resistant anti-corrosion filler still has an interfacial shear strength greater than 15 MPa and an electrochemical corrosion rate of <5 μA / cm². High-temperature resistant, acid-resistant, and corrosion-resistant filler material can be used for a long time at 150℃, with a performance degradation rate of <5% within 3000 hours.

[0035] The prepared filler material was subjected to performance tests. After curing, the conductivity of the filler material was measured using the four-probe method, and the conductivity of the conductive plate was greater than 18 S / cm. To prevent corrosion of the copper sheet by acid solution, the filler material was used for protection. During the experiment, the filler material around the overlap between the sample copper sheet and the conductive composite board was removed. The bonding strength between the copper sheet and the conductive composite board was measured to be around 30 MPa using the overlap shear test method. An aging test was conducted in 65% sulfuric acid solution, and the copper sheet was immersed in 65% sulfuric acid solution for 12 months at three different temperatures: -60℃, room temperature, and 80℃. The bonding strength between the copper sheet and the conductive composite board was measured to be greater than 15 MPa. The electrochemical corrosion rate in 65% sulfuric acid solution was measured using the electrochemical linear polarization method and was <5 μA / cm. 2 .

[0036] Example 1 The preparation method of the high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material in this embodiment is as follows: S1. Mix titanate and deionized water at a mass ratio of 2:400 and stir magnetically at 45°C for 10 min to obtain a titanate hydrated solution; wherein the titanate is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester at a mass ratio of 1:0.5.

[0037] Isopropanol, bisphenol A epoxy resin and γ-aminopropyltriethoxysilane were mixed at a mass ratio of 200:75:1.5 and stirred at 60°C for 15 min. Flake graphite (100 mesh), conductive carbon black (30 nm), and carbon nanofibers (50 nm in diameter and 5 μm in length) were mixed in a mass ratio of 100:5:3 to obtain a multi-component mixed conductive filler. The filler was then subjected to plasma treatment at 300 W for 8 min under an argon atmosphere with a flow rate of 20 sccm. The plasma-treated multi-component mixed conductive filler was then added to a titanate hydrate solution and stirred at 45 °C for 20 min to complete the modification, thus preparing a dual-modified conductive filler. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 108:405. S2. The double-modified conductive filler and titanate hydrate solution are mixed at a mass ratio of 108:405. The mixture is first sheared at a shear rate of 2500 r / min for 20 min to obtain a mixed slurry. The mixed slurry is then spread to a thickness of 2.5 mm to 2.9 mm and vacuum extracted at 80 °C for 1 h to obtain conductive material powder. S3. The conductive material powder and modified epoxy resin are mixed at a mass ratio of 510:276.5. First, the mixture is sheared at a high speed of 2500 r / min for 30 min. Then, it is ultrasonically dispersed at a power of 200 W and a frequency of 40 kHz for 10 min to obtain the filler material component A.

[0038] S4. The crosslinking agent (adipic acid and sebacic acid in a mass ratio of 3:1) and the catalyst (benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1) are mixed at a mass ratio of 62:0.8. The mixture is magnetically stirred at room temperature for 10 minutes. Then, antioxidant 1010 is added at a mass ratio of 0.3% of the crosslinking agent, and the mixture is stirred for another 5 minutes to obtain component B of the filler material. S5. Mix filler component A and filler component B thoroughly at a mass ratio of 790:65, then apply to the surface of carbon fiber material. Pre-cur at 80℃ for 30 min, then cure at 120℃ for 1.5 h, then cure at 150℃ for 30 min. Cool to room temperature to obtain high temperature resistant, acid resistant and corrosion resistant filler material.

[0039] The high-temperature resistant, acid-resistant, and corrosion-resistant filler material prepared in this embodiment has an electrical conductivity ≥18S / cm and an interfacial shear strength ≥40MPa with carbon fiber material. After being immersed in 65% sulfuric acid solution for 12 months, the interfacial shear strength is still greater than 15MPa, and the electrochemical corrosion rate is <5μA / cm². It can be used for a long time at 150℃, and the performance degradation rate is <5% within 3000h.

[0040] Performance test results: The filler material prepared in this embodiment was tested for performance. The conductivity was measured to be 18.2 S / cm using the four-probe method; the interfacial shear strength with carbon fiber was measured to be 40.5 MPa using the shear test method; after immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength was 15.8 MPa; the corrosion rate was measured to be 4.2 μA / cm² using the electrochemical linear polarization method; and after 3000 hours of service at a constant temperature of 150℃, the performance degradation rate was 3.1%. When applied to a copper sheet for protection and bonded to a conductive composite material plate, the initial bonding strength was measured to be 30.2 MPa. After immersion in 65% sulfuric acid solution at -60℃, room temperature, and 80℃ for 12 months, the bonding strength remained ≥15.5 MPa. The conductivity measured by the four-probe method was 18.2 S / cm, which is much higher than the 15 S / cm of the existing technology. This solves the problem of "insufficient conductivity of traditional filler materials or corrosion failure of metal fillers", and can effectively reduce the interfacial contact resistance between carbon materials and metal current collectors, ensuring conductivity efficiency.

[0041] Example 2 The preparation method of the high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material in this embodiment is as follows: S1. Mix titanate and deionized water at a mass ratio of 2:410 and stir magnetically at 48°C for 12 min to obtain a titanate hydrated solution; wherein the titanate is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester at a mass ratio of 1:0.6.

[0042] Isopropanol, bisphenol A epoxy resin and γ-aminopropyltriethoxysilane were mixed at a mass ratio of 205:76:1.8 and stirred at 62℃ for 16 min. Flake graphite (120 mesh), conductive carbon black (32 nm), and carbon nanofibers (60 nm in diameter and 6 μm in length) were mixed at a mass ratio of 100:5.2:3.2 to obtain a multi-component mixed conductive filler. The filler was then subjected to plasma treatment at 320 W for 9 min under an argon atmosphere with a flow rate of 22 sccm. The plasma-treated multi-component mixed conductive filler was then added to a titanate hydrate solution and stirred at 48 °C for 22 min to complete the modification, thus preparing a dual-modified conductive filler. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 109:410. S2. The double-modified conductive filler and titanate hydrate solution are mixed at a mass ratio of 108:410. The mixture is first sheared at a shear rate of 2700 r / min for 22 min to obtain a mixed slurry. The mixed slurry is then spread to a thickness of 2.5 mm to 2.9 mm and vacuum extracted at 85 °C for 1.2 h to obtain conductive material powder. S3. The conductive material powder and modified epoxy resin are mixed at a mass ratio of 530:280. First, the mixture is sheared at a high speed of 2700 r / min for 22 min. Then, it is ultrasonically dispersed at a power of 220 W and a frequency of 40 kHz for 11 min to obtain the filler material component A.

[0043] S4. The crosslinking agent (adipic acid and sebacic acid in a mass ratio of 3:1) and the catalyst (benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1) are mixed at a mass ratio of 63:0.85. The mixture is then magnetically stirred at room temperature for 11 minutes. Antioxidant 1010, accounting for 0.3% of the mass of the crosslinking agent, is added and the mixture is stirred for another 8 minutes to obtain component B of the filler material. S5. Mix filler component A and filler component B thoroughly at a mass ratio of 786.5:62.8, then apply the mixture to the surface of the carbon fiber material. Pre-cur at 82℃ for 32 min, then cure at 122℃ for 1.6 h, then cure at 152℃ for 30 min. Cool to room temperature to obtain a high-temperature resistant, acid-resistant, and corrosion-resistant filler material.

[0044] Performance test results: The filler material prepared in this embodiment was tested for performance. The conductivity was measured to be 18.5 S / cm using the four-probe method, and the interfacial shear strength with carbon fiber was measured to be 41.2 MPa using the shear test method. After immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength was 16.1 MPa, and the corrosion rate was measured to be 3.8 μA / cm² using the electrochemical linear polarization method. After 3000 hours of service at a constant temperature of 150℃, the performance degradation rate was 2.8%. The coating was applied to a copper sheet for protection and then bonded to a conductive composite material plate. The initial bonding strength was measured to be 30.5 MPa. After immersion in 65% sulfuric acid solution at -60℃, room temperature, and 80℃ for 12 months, the bonding strength was ≥15.8 MPa and the conductivity was 18.5 S / cm, meeting the high conductivity requirement and adapting to the conductivity requirements of flow batteries. The interfacial shear strength was 41.2 MPa, solving the problem of easy separation at the interface of carbon materials. The strength after acid immersion was 16.1 MPa and the corrosion rate was 3.8 μA / cm², solving the problem of long-term service failure under acidic conditions. The attenuation rate after 3000 hours of service at 150℃ was 2.8%, solving the problem of poor high-temperature resistance of single graphite powder.

[0045] Example 3 The preparation method of the high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material in this embodiment is as follows: S1. Mix titanate and deionized water at a mass ratio of 2.25:425 and stir magnetically at 50°C for 13 min to obtain a titanate hydrated solution; wherein the titanate is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester at a mass ratio of 1:0.8.

[0046] Isopropanol, bisphenol A epoxy resin and γ-aminopropyltriethoxysilane were mixed at a mass ratio of 210:77:2 and stirred at 65°C for 18 min. Flake graphite (150 mesh), conductive carbon black (35 nm), and carbon nanofibers (70 nm in diameter and 8 μm in length) were mixed at a mass ratio of 100:5.5:3.5 to obtain a multi-component mixed conductive filler. The filler was then subjected to plasma treatment at 330 W for 10 min under an argon atmosphere with a flow rate of 25 sccm. The plasma-treated multi-component mixed conductive filler was then added to a titanate hydrate solution and stirred at 50 °C for 25 min to complete the modification, thus preparing a dual-modified conductive filler. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 110:425. S2. The double-modified conductive filler and titanate hydrate solution are mixed at a mass ratio of 110:402~425. The mixture is first sheared at a shear rate of 2800 r / min for 25 min to obtain a mixed slurry. The mixed slurry is then spread to a thickness of 2.5 mm~2.9 mm and vacuum extracted at 100℃ for 2 h to obtain conductive material powder. S3. The conductive material powder and modified epoxy resin are mixed at a mass ratio of 550:290. First, the mixture is sheared at a high speed of 2800 r / min for 25 min. Then, it is ultrasonically dispersed at a power of 230 W and a frequency of 40 kHz for 13 min to obtain the filler component A.

[0047] S4. The crosslinking agent (adipic acid and sebacic acid in a mass ratio of 3:1) and the catalyst (benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1) are mixed at a mass ratio of 64:0.9. The mixture is magnetically stirred at room temperature for 13 minutes. Then, antioxidant 1010, accounting for 0.4% of the mass of the crosslinking agent, is added and the mixture is stirred for another 10 minutes to obtain component B of the filler material. S5. Mix filler component A and filler component B thoroughly at a mass ratio of 800:63.5, then apply to the surface of carbon fiber material. Pre-cur at 85℃ for 35 min, then cure at 125℃ for 1.8 h, then cure at 155℃ for 30 min. Cool to room temperature to obtain high temperature resistant, acid resistant and corrosion resistant filler material.

[0048] Performance test results: The filler material prepared in this embodiment was tested for performance. The conductivity was measured to be 19.1 S / cm using the four-probe method; the interfacial shear strength with carbon fiber was measured to be 42.0 MPa using the shear test method; after immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength was 16.5 MPa; the corrosion rate was measured to be 3.5 μA / cm² using the electrochemical linear polarization method; after 3000 hours of service at a constant temperature of 150℃, the performance degradation rate was 2.5%. When applied to a copper sheet for protection and overlapped with a conductive composite material plate, the initial bonding strength was measured to be 31.0 MPa. After immersion in 65% sulfuric acid solution at -60℃, room temperature, and 80℃ for 12 months, the bonding strength remained ≥16.0 MPa, and the conductivity was 19.1 S / cm, thus solving the problem of high interfacial contact resistance in carbon materials and ensuring conductivity efficiency. The interfacial shear strength was 42.0 MPa, addressing the core pain point of poor adhesion between traditional filler materials and carbon powder. After acid immersion, the strength was 16.5 MPa and the corrosion rate was 3.5 μA / cm², resolving the contradiction between the corrosion of metal fillers and the insufficient mechanical properties of single graphite powder. The attenuation rate after 3000 hours of service at 150℃ was 2.5%, solving the problem of rapid performance degradation under harsh environments.

[0049] Example 4 The preparation method of the high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material in this embodiment is as follows: S1. The titanate ester and deionized water are mixed at a mass ratio of 2.4:440 and magnetically stirred at 52°C for 15 min to obtain a titanate ester hydrated solution; wherein the titanate ester is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester at a mass ratio of 1:0.9.

[0050] Isopropanol, bisphenol A epoxy resin and γ-aminopropyltriethoxysilane were mixed at a mass ratio of 215:79:2.3 and stirred at a constant temperature of 68℃ for 19 min. Flake graphite (180 mesh), conductive carbon black (38 nm), and carbon nanofibers (80 nm in diameter and 9 μm in length) were mixed at a mass ratio of 100:5.8:3.8 to obtain a multi-component mixed conductive filler. The filler was then subjected to plasma treatment at 340 W for 11 min under an argon atmosphere with a flow rate of 28 sccm. The plasma-treated multi-component mixed conductive filler was then added to a titanate hydrate solution and stirred at 52 °C for 28 min to complete the modification, thus preparing a dual-modified conductive filler. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 112:440. S2. The double-modified conductive filler and titanate hydrate solution are mixed at a mass ratio of 112:440. The mixture is first sheared at a shear rate of 2900 r / min for 20 min to obtain a mixed slurry. The mixed slurry is then spread to a thickness of 2.5 mm to 2.9 mm and vacuum extracted at 115 °C for 2.5 h to obtain conductive material powder. S3. The conductive material powder and modified epoxy resin are mixed at a mass ratio of 560:300. First, the mixture is sheared at a high speed of 2900 r / min for 28 min. Then, it is ultrasonically dispersed at a power of 240 W and a frequency of 40 kHz for 14 min to obtain the filler material component A.

[0051] S4. The crosslinking agent (adipic acid and sebacic acid in a mass ratio of 3:1) and the catalyst (benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1) are mixed at a mass ratio of 64:0.8. The mixture is magnetically stirred at room temperature for 15 minutes. Then, antioxidant 1010, accounting for 0.5% of the mass of the crosslinking agent, is added and the mixture is stirred for another 10 minutes to obtain component B of the filler material. S5. Mix filler component A and filler component B thoroughly at a mass ratio of 830:64, then apply to the surface of carbon fiber material. Pre-cur at 88℃ for 38 min, then cure at 128℃ for 2 h, then cure at 158℃ for 30 min. Cool to room temperature to obtain high temperature resistant, acid resistant and corrosion resistant filler material.

[0052] Performance test results: The filler material prepared in this embodiment was tested for performance. The conductivity was measured to be 18.8 S / cm using the four-probe method; the interfacial shear strength with carbon material was measured to be 41.5 MPa using the shear test method; after immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength was 16.2 MPa; the corrosion rate was measured to be 3.7 μA / cm² using the electrochemical linear polarization method; after 3000 hours of service at a constant temperature of 150℃, the performance degradation rate was 2.7%. The coating was applied to a copper sheet for protection and then bonded to a conductive composite material plate. The initial bonding strength was measured to be 30.8 MPa. After immersion in 65% sulfuric acid solution at -60℃, room temperature, and 80℃ for 12 months, the bonding strength was ≥15.9 MPa and the conductivity was 18.8 S / cm, thus solving the problem of the trade-off between conductivity and corrosion resistance. The interfacial shear strength was 41.5 MPa, solving the problem of carbon powder interface bonding and ensuring long-term stability. The strength after acid immersion was 16.2 MPa and the corrosion rate was 3.7 μA / cm², solving the problem of material failure in acidic environments. The attenuation rate after 3000 hours of service at 150℃ was 2.7%, solving the problem of insufficient stability under high-temperature conditions.

[0053] Example 5 The preparation method of the high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material in this embodiment is as follows: S1. Mix titanate and deionized water at a mass ratio of 2.5:450 and stir magnetically at 55°C for 15 min to obtain a titanate hydrated solution; wherein the titanate is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester at a mass ratio of 1:1.

[0054] Isopropanol, bisphenol A epoxy resin and γ-aminopropyltriethoxysilane were mixed at a mass ratio of 220: 80: 2.5 and stirred at 70°C for 20 min. Flake graphite (200 mesh), conductive carbon black (40 nm), and carbon nanofibers (80 nm in diameter and 10 μm in length) were mixed in a mass ratio of 100:6:4 to obtain a multi-component mixed conductive filler. The filler was then subjected to plasma treatment at 350 W for 12 min under an argon atmosphere with a flow rate of 30 sccm. The plasma-treated multi-component mixed conductive filler was then added to a titanate hydrate solution and stirred at 55 °C for 30 min to complete the modification, thus preparing a dual-modified conductive filler. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 113:450. S2. The double-modified conductive filler and titanate hydrate solution are mixed at a mass ratio of 113:450. The mixture is first sheared at a shear rate of 3000 r / min for 30 min to obtain a mixed slurry. The mixed slurry is then spread to a thickness of 2.5 mm to 2.9 mm and vacuum extracted at 120 °C for 3 h to obtain conductive material powder. S3. The conductive material powder and modified epoxy resin are mixed at a mass ratio of 565.5:302.5. First, the mixture is sheared at a high speed of 3000 r / min for 30 min. Then, it is ultrasonically dispersed at a power of 250 W and a frequency of 40 kHz for 15 min to obtain the filler component A.

[0055] S4. The crosslinking agent (adipic acid and sebacic acid in a mass ratio of 3:1) and the catalyst (benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1) are mixed at a mass ratio of 65:0.9. The mixture is magnetically stirred at room temperature for 15 minutes. Then, antioxidant 1010 is added at 0.5% of the mass of the crosslinking agent, and the mixture is stirred for another 8 minutes to obtain component B of the filler material. S5. Mix filler component A and filler component B thoroughly at a mass ratio of 850:64.5, then apply to the surface of carbon fiber material. Pre-cur at 90℃ for 40 min, then cure at 130℃ for 2 h, then cure at 160℃ for 30 min. Cool to room temperature to obtain high temperature resistant, acid resistant and corrosion resistant filler material.

[0056] Performance test results: The filler material prepared in this embodiment was tested for performance. The conductivity was measured to be 19.3 S / cm using the four-probe method; the interfacial shear strength with carbon fiber was measured to be 42.3 MPa using the shear test method; after immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength was 16.8 MPa; the corrosion rate was measured to be 3.3 μA / cm² using the electrochemical linear polarization method; after 3000 hours of service at a constant temperature of 150℃, the performance degradation rate was 2.2%. When applied to a copper sheet for protection and bonded to a conductive composite board, the initial bonding strength was measured to be 31.2 MPa. After immersion in 65% sulfuric acid solution at -60℃, room temperature, and 80℃ for 12 months, the bonding strength remained ≥16.2 MPa. When applied to a copper sheet for protection and bonded to a conductive composite board, the initial bonding strength was 30.2 MPa. After immersion in 65% sulfuric acid solution at different temperatures for 12 months, the bonding strength remained ≥15.5 MPa, meeting the application requirements in harsh environments such as flow batteries and marine engineering. The conductivity of 19.3 S / cm addresses the low conductivity of carbon material interfaces, ensuring power transmission. The interfacial shear strength of 42.3 MPa addresses the problem of easy separation between traditional filler materials and carbon powder. The strength after acid immersion is 16.8 MPa, and the corrosion rate is 3.3 μA / cm², addressing the failure of metal fillers and the performance limitations of single graphite powder. The attenuation rate of 2.2% after 3000 hours of service at 150℃ addresses the problem of short service life under harsh environments.

[0057] Example 6 The preparation method of the high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material in this embodiment is as follows: S1. Mix titanate and deionized water at a mass ratio of 2:400 and stir magnetically at 45°C for 10 min to obtain a titanate hydrated solution; wherein the titanate is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester at a mass ratio of 1:0.5.

[0058] Isopropanol, bisphenol A epoxy resin and γ-aminopropyltriethoxysilane were mixed at a mass ratio of 200:75:1.5 and stirred at 60°C for 15 min. Flake graphite (100 mesh), conductive carbon black (30 nm), and carbon nanofibers (50 nm in diameter and 8 μm in length) were mixed in a mass ratio of 100:5:3 to obtain a multi-component mixed conductive filler. The filler was then subjected to plasma treatment at 300 W for 12 min under an argon atmosphere with a flow rate of 30 sccm. The plasma-treated multi-component mixed conductive filler was then added to a titanate hydrate solution and stirred at 45 °C for 20 min to complete the modification, thus preparing a dual-modified conductive filler. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 108:402. S2. The double-modified conductive filler and titanate hydrate solution are mixed at a mass ratio of 108:402. The mixture is first sheared at a shear rate of 3000 r / min for 30 min to obtain a mixed slurry. The mixed slurry is then spread to a thickness of 2.5 mm to 2.9 mm and vacuum extracted at 120 °C for 3 h to obtain conductive material powder. S3. The conductive material powder and modified epoxy resin are mixed at a mass ratio of 565.5:300. First, the mixture is sheared at a high speed of 2700 r / min for 22 min; then, it is ultrasonically dispersed at a power of 220 W and a frequency of 40 kHz for 11 min to obtain the filler material component A.

[0059] S4. The crosslinking agent (adipic acid and sebacic acid in a mass ratio of 3:1) and the catalyst (benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:1) are mixed at a mass ratio of 62~65:0.8~0.9. The mixture is magnetically stirred at room temperature for 15 minutes. Then, antioxidant 1010 is added at 0.5% of the mass of the crosslinking agent, and the mixture is stirred for another 10 minutes to obtain component B of the filler material. S5. Mix filler component A and filler component B thoroughly at a mass ratio of 868:65.9, then apply to the surface of carbon fiber material. Pre-cur at 90℃ for 40 min, then cure at 130℃ for 2 h, then cure at 160℃ for 30 min. Cool to room temperature to obtain high temperature resistant, acid resistant and corrosion resistant filler material.

[0060] Performance test results: The filler material prepared in this embodiment was tested for performance. The conductivity was measured to be 18.9 S / cm using the four-probe method, and the interfacial shear strength with carbon fiber was measured to be 41.8 MPa using the shear test method. After immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength was 16.4 MPa, and the corrosion rate was measured to be 3.6 μA / cm² using the electrochemical linear polarization method. After 3000 hours of service at a constant temperature of 150℃, the performance degradation rate was 2.6%. The material was applied to a copper sheet for protection and then bonded to a conductive composite board. The initial bonding strength was measured to be 30.9 MPa. After immersion in 65% sulfuric acid solution at -60℃, room temperature, and 80℃ for 12 months, the bonding strength was ≥15.9 MPa and the conductivity was 18.9 S / cm, thus solving the problem of insufficient conductivity of existing filler materials. The interfacial shear strength was 41.8 MPa, thus solving the problem of poor compatibility caused by the inertness of the carbon powder surface. The strength after acid immersion was 16.4 MPa and the corrosion rate was 3.6 μA / cm², thus solving the problem of performance degradation in acidic environments. The degradation rate after 3000 hours of service at 150℃ was 2.6%, thus solving the problem of poor adaptability to harsh environments.

[0061] Comparative Example 1 (no dual-modified conductive filler used, only single plasma modification) In this comparative example, the preparation steps, raw material ratios, and process parameters of the epoxy resin carbon-based filler material are completely consistent with those of Example 3 of this invention, except that in S1 only the multi-component mixed conductive filler is plasma modified and no secondary modification with titanate hydrate solution is performed.

[0062] Performance test results: The electrical conductivity of the prepared filler material is 12.5 S / cm, and the interfacial shear strength with carbon fiber material is 28.3 MPa; after immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength is only 8.2 MPa, and the electrochemical corrosion rate is 12.5 μA / cm²; after 3000 hours of service at 150℃, the performance degradation rate is 18.3%; the initial bonding strength of the copper sheet overlap is 20.5 MPa, and after immersion in 65% sulfuric acid solution at different temperatures for 12 months, the bonding strength drops to below 7.5 MPa.

[0063] Results analysis: Without the use of plasma + titanate dual modification process, plasma modification alone cannot form stable adhesive groups on the filler surface. The poor compatibility between the filler and the epoxy resin matrix leads to a significant decrease in conductivity and interfacial bonding strength. Furthermore, in acidic and high-temperature environments, the filler is prone to separation from the matrix, resulting in severe performance degradation and failure to meet the service requirements of harsh environments.

[0064] Comparative Example 2 (using traditional single-temperature curing, without step-by-step gradient curing) In this comparative example, the preparation of epoxy resin carbon-based filler material was completely consistent with Example 3 of the present invention, except that in S5, the traditional single temperature curing of 120℃ for 3 hours was used and stepwise gradient curing was not performed.

[0065] Performance test results: The electrical conductivity of the prepared filler material is 16.3 S / cm, and the interfacial shear strength with carbon fiber material is 32.5 MPa; after immersion in 65% sulfuric acid solution for 12 months, the interfacial shear strength is 10.8 MPa, and the electrochemical corrosion rate is 8.6 μA / cm²; after 3000 hours of service at 150℃, the performance degradation rate is 11.5%; the initial bonding strength of the copper sheet overlap is 25.3 MPa, and after immersion in 65% sulfuric acid solution at different temperatures for 12 months, the bonding strength drops to below 9.8 MPa.

[0066] Results analysis: Traditional single-temperature curing process easily leads to large internal stress in the filler material, forming microcracks. Acid can easily penetrate to the interface layer through the microcracks, causing interface separation. At the same time, the microcracks will continue to expand under high temperature service, resulting in rapid decay of electrical conductivity and mechanical strength. Its high temperature resistance and acid corrosion resistance are far inferior to the stepwise gradient curing process of this invention.

Claims

1. A method for preparing high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material, characterized in that, Specifically as follows: S1. Raw material preparation and pretreatment: Prepare titanate hydrate solution, modified epoxy resin and double-modified conductive filler respectively; S2. The double-modified conductive filler is mixed with a titanate hydrate solution, sheared at high speed, spread and then vacuum extracted to obtain conductive material powder. S3. The conductive material powder is mixed with the modified epoxy resin, and then sheared and ultrasonically dispersed to obtain the filler component A. S4. The crosslinking agent and catalyst are magnetically mixed, and an antioxidant is added to obtain the filler material component B. S5. Mix the filler component A and filler component B and apply them to the surface of the carbon material. Perform pre-curing and step-by-step gradient curing and shaping. Cool to room temperature to obtain the target filler material.

2. The preparation method of the high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material according to claim 1, characterized in that, The specific method for preparing the titanate hydrate solution in S1 is as follows: A uniformly dispersed titanate hydrated solution is obtained by mixing titanate ester with deionized water at a mass ratio of 2~2.5:400~450 and stirring magnetically at a temperature of 45℃~55℃ for 10min~15min. The titanate is a compound of triisostearoyl titanate isopropyl ester and bis(ethyl acetoacetate) titanate diisopropyl ester in a mass ratio of 1:0.5~1.

3. The preparation method of the high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material according to claim 2, characterized in that, The specific preparation method of the modified epoxy resin in S1 is as follows: The modified epoxy resin can be obtained by mixing the diluent, epoxy resin and silane coupling agent and stirring at a constant temperature of 60℃~70℃ for 15 min~20 min. The mass ratio of the diluent to the epoxy resin is 200~220:75~80, and the mass ratio of the diluent to the silane coupling agent is 200~220:1.5~2.5; The diluent is isopropanol; The epoxy resin is a bisphenol A type epoxy resin; The silane coupling agent is γ-aminopropyltriethoxysilane.

4. The preparation method of the high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material according to claim 3, characterized in that, The specific preparation method of the dual-modified conductive filler in S1 is as follows: Flake graphite, conductive carbon black and carbon nanofibers were stirred and mixed to obtain a multi-component mixed conductive filler. The multi-component mixed conductive filler was placed in an argon atmosphere and subjected to plasma treatment at a power of 300W~350W for 8min~12min. Then, the plasma-treated multi-component mixed conductive filler was added to a titanate hydrate solution and modified by constant temperature stirring at 45℃~55℃ for 20min~30min to obtain a double-modified conductive filler. The mass ratio of flake graphite to conductive carbon black is 100:5~6, and the mass ratio of flake graphite to carbon nanofiber is 100:3~4. The mass ratio of the multi-component mixed conductive filler to the titanate hydrate solution is 108~113:402~452.5; The particle size of the flake graphite is 100-200 mesh, the particle size of the conductive carbon black is 30-40 nm, the diameter of the carbon nanofiber is 50-80 nm, and the length of the carbon nanofiber is 5-10 μm. During plasma treatment, the argon flow rate is 20 sccm to 30 sccm.

5. The preparation method of the high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material according to claim 4, characterized in that, The specific method of S2 is as follows: The dual-modified conductive filler and titanate hydrate solution were mixed at a mass ratio of 108~113:402~452.

5. The mixture was first sheared at a shear rate of 2500r / min~3000r / min for 20min~30min to obtain a mixed slurry. The mixed slurry was then spread into a thin layer with a thickness of 2.5mm~2.9mm and vacuum extracted at 80℃~120℃ for 1h~3h to obtain conductive material powder.

6. The preparation method of the high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material according to claim 5, characterized in that, The specific method of S3 is as follows: Conductive material powder and modified epoxy resin are mixed at a mass ratio of 510~565.5:276.5~302.

5. The mixture is first sheared at a shear rate of 2500r / min~3000r / min for 20min~30min, and then ultrasonically dispersed at a power of 200W~250W and a frequency of 40kHz for 10min~15min to obtain the filler component A.

7. The preparation method of the high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material according to claim 6, characterized in that, The specific method of S4 is as follows: The crosslinking agent and catalyst are magnetically stirred at room temperature for 10-15 minutes at a mass ratio of 62-65:0.8-0.9 to ensure thorough mixing. Then, antioxidant 1010 is added at a mass ratio of 0.3%-0.5% of the crosslinking agent, and stirring is continued for 5-10 minutes to obtain component B of the filler material. The crosslinking agent is a mixture of adipic acid and sebacic acid in a mass ratio of 3:

1. The catalyst is a mixture of benzyl dimethylamine and 2-methylimidazole in a mass ratio of 2:

1.

8. The preparation method of the high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material according to claim 7, characterized in that, The specific method of S5 is as follows: Mix filler component A and filler component B thoroughly at a mass ratio of 786.5~868:62.8~65.9, then apply the mixture to the surface of the carbon material. Use a stepwise gradient curing process: first pre-cur at 80℃~90℃ for 30min~40min, then cure at 120℃~130℃ for 1.5~2h, and finally cure at 150℃~160℃ for 30min. Cool to room temperature to obtain a high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material.

9. The high-performance epoxy carbon-based high-temperature resistant and acid-resistant anti-corrosion filler material prepared by any one of the preparation methods according to claims 1 to 8, characterized in that, The high-performance epoxy carbon-based high-temperature resistant, acid-resistant, and corrosion-resistant filler material has an electrical conductivity of ≥18S / cm and an interfacial shear strength with carbon fiber material of ≥40MPa. The high-performance epoxy carbon-based high-temperature and acid-resistant anti-corrosion filler material, after being immersed in 65% sulfuric acid solution for 12 months, exhibits an interfacial shear strength greater than 15 MPa and an electrochemical corrosion rate less than 5 μA / cm². The high-performance epoxy carbon-based high-temperature and acid-resistant anti-corrosion filler material has a performance degradation rate of <5% within 3000 hours when used at 150℃.