Anti-corrosion fireproof coating applied to new energy battery box and preparation method of anti-corrosion fireproof coating

Abstract

The invention discloses an anti-corrosion fireproof coating applied to a new energy battery box and a preparation method, and relates to the technical field of industrial coatings, the anti-corrosion fireproof coating comprises the following specific components: a base resin system, a curing agent, a functional filler system, a flame retardant system, a solvent system and an auxiliary agent system; the anticorrosive and fireproof coating further comprises additives, wherein the additives specifically comprise a functionalized MXene loaded lithium ion adsorbent, a metal organic framework encapsulated quaternary phosphonium salt, polyaryletherketone coated antimony trioxide nano-particles and boron-nitrogen co-doped graphene aerogel powder; the material is prepared based on the materials. According to the invention, multiple additives are synergistically introduced into a traditional basic coating system, and on the basis of a basic flame-retardant and anti-corrosion structure, lithium ion directional adsorption, gas-phase free radical active intervention, high-temperature carbonization barrier construction and three-dimensional thermal barrier network configuration are further realized; therefore, the multi-dimensional safety performance of the coating in battery thermal runaway, salt spray corrosion and high-temperature impact environments is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial coatings, and specifically to an anti-corrosion and fire-proof coating for new energy battery boxes and a preparation method thereof. Background Art

[0002] With the rapid development of the new energy vehicle industry, as the core component, the power battery has put forward more stringent requirements for the anti-corrosion and fire-proof performance of the battery box structure. Currently, the protective coatings widely used in battery boxes are mostly based on epoxy, polyurethane or silicone resins, combined with phosphorus-nitrogen or halogen-substituted flame retardants, and achieve certain thermal protection and corrosion inhibition functions through the film-forming heat insulation and carbonization barrier mechanisms. However, the existing technologies generally have the following technical deficiencies:

[0003] On the one hand, although traditional flame retardant additives such as aluminum hydroxide, phosphate esters, antimony trioxide, etc. have certain flame retardant properties, their release rates are uncontrollable under actual high-temperature thermal runaway conditions, and the flame retardant reaction response is delayed. It is difficult to achieve rapid thermal barrier and gas-phase intervention during the thermal runaway process of lithium-ion batteries, and it is easy to cause flame spread and structural damage.

[0004] On the other hand, the existing anti-corrosion systems mostly establish a barrier layer by using flaky fillers or surface coatings, and cannot deeply capture metal ions or corrosive by-products in the electrolyte, resulting in prominent problems of lithium salt penetration and corrosion accumulation during long-term service, especially more serious in high-temperature or electrolyte leakage environments.

[0005] Therefore, there is an urgent need for a new type of functionalized anti-corrosion and fire-proof coating system that integrates high-response flame retardant performance, high-temperature ion adsorption function, and thermal insulation and conductive isolation structure to achieve full-cycle high-safety protection for the structure of new energy battery boxes. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides an anti-corrosion and fire-proof coating for new energy battery boxes and a preparation method thereof to solve the problems raised in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An embodiment of the present invention provides an anti-corrosion and fire-proof coating for new energy battery boxes, which includes the following specific components:

[0009] Base resin system, curing agent, functional filler system, flame retardant system, solvent system, additive system;

[0010] The anti-corrosion and fire-proof coating further includes additives, and the additives specifically include:

[0011] Functionalized MXene-supported lithium ion adsorbent, metal-organic framework encapsulated quaternary phosphonium salt, polyaryletherketone-coated antimony trioxide nanoparticles, boron and nitrogen co-doped graphene aerogel powder.

[0012] Further optimizing this technical solution, among the specific components:

[0013] The base resin system uses medium to high molecular weight epoxy resin;

[0014] The curing agent uses a compound curing agent of modified aliphatic amine and phenolic amine;

[0015] The functional filler system uses sheet-structured fillers, including mica powder, sheet-shaped aluminum silicate, and glass flakes;

[0016] The flame retardant system uses environmentally friendly non-halogen flame retardants, including melamine polyphosphate and microencapsulated red phosphorus particles;

[0017] The solvent system includes xylene, butanol, and cyclohexanone;

[0018] The additive system includes a wetting and dispersing agent and an antifoaming agent.

[0019] Further optimizing this technical solution, the mass parts of the specific components are as follows:

[0020] The base resin system is 30 - 50 parts;

[0021] The curing agent is 5 - 15 parts;

[0022] The functional filler system is 10 - 30 parts;

[0023] The flame retardant system is 10 - 20 parts;

[0024] The solvent system is 10 - 25 parts;

[0025] The additive system is 1 - 3 parts.

[0026] Further optimizing this technical solution, the mass parts of the additives are as follows:

[0027] The functionalized MXene-supported lithium ion adsorbent is 1 - 3 parts;

[0028] The metal-organic framework encapsulated quaternary phosphonium salt is 0.5 - 2.0 parts;

[0029] The polyaryletherketone-coated antimony trioxide nanoparticles are 1 - 2 parts;

[0030] The boron and nitrogen co-doped graphene aerogel powder is 0.5 - 1.5 parts.

[0031] To further optimize this technical solution, the functionalized MXene-supported lithium ion adsorbent is mainly composed of Ti3C2Tx type MXene two-dimensional material, where Tx is a surface functional group. The MXene surface is grafted with sulfonic acid group -SO3H and carboxyl group -COOH functional groups, and loaded with lithium aluminum hydrotalcite-like compound nanoparticles, which are used to adsorb free lithium ions in the event of electrolyte leakage inside the battery box.

[0032] To further optimize this technical solution, the metal-organic framework encapsulated quaternary phosphonium salt includes a ZIF-8 type metal-organic framework and a quaternary phosphonium salt compound encapsulated in the pore structure of this framework;

[0033] The metal center of the ZIF-8 type metal-organic framework is Zn 2+ , and the ligand is an imidazole group;

[0034] The quaternary phosphonium salt has a tetraphenylphosphonium structure with a sulfonate substituent, including tetraphenylphosphonium sulfonate;

[0035] The average particle size of the metal-organic framework encapsulated quaternary phosphonium salt is in the range of 200 - 500 nm.

[0036] To further optimize this technical solution, the polyaryletherketone-coated antimony trioxide nanoparticles include antimony trioxide Sb2O3 nanoparticles with a particle size of 80 - 120 nm, and a polyaryletherketone polymer coating layer uniformly coated on its surface. The thickness of the polyaryletherketone polymer coating layer is 20 - 30 nm;

[0037] The coating layer decomposes to release aromatic free radicals, enhancing the reaction capture effect of Sb2O3 with free radicals, and is used to improve the gas-phase flame retardancy efficiency.

[0038] To further optimize this technical solution, the boron and nitrogen co-doped graphene aerogel powder includes a three-dimensional porous graphene structure co-doped with a boron source and a nitrogen source. The graphene aerogel has a honeycomb-like spatial network structure; among them, boron element doping guides the stable formation of the high-temperature carbon skeleton, and nitrogen element doping enhances the gas-phase fire suppression reaction activity.

[0039] A preparation method of an anti-corrosion and fire-proof coating applied to a new energy battery box, which is prepared based on the above anti-corrosion and fire-proof coating, includes the following specific steps:

[0040] S1. Predispersion of the basic resin system;

[0041] S2. Synergistic pre-adjustment of the additive system and the solvent system;

[0042] S3. Addition and stable dispersion of the functional filler system;

[0043] S4. Composite integration of the flame retardant system;

[0044] S5. Introduction of functionalized MXene-supported lithium ion adsorbent;

[0045] S6. Gradient dispersion of phosphonium salt encapsulated in metal-organic framework;

[0046] S7. Addition of polyaryletherketone-coated antimony trioxide nanoparticles;

[0047] S8. Final introduction and stabilization of boron and nitrogen co-doped graphene aerogel powder.

[0048] To further optimize this technical solution, the method further includes performance testing of the prepared anti-corrosion and fire-proof coating samples, including thermal stability testing, heat insulation and fire-proof testing, flame retardancy rating evaluation, smoke density rating detection, salt spray corrosion testing, adhesion testing, damp heat resistance testing, thermal shock cycle testing, lithium ion adsorption performance testing, and quality stability detection.

[0049] Compared with the prior art, the present invention provides an anti-corrosion and fire-proof coating for new energy battery boxes and a preparation method thereof, having the following beneficial effects:

[0050] The anti-corrosion and fire-proof coating for new energy battery boxes and the preparation method thereof, by synergistically introducing various additives in the traditional basic coating system, on the basis of having the basic flame retardant and anti-corrosion structures, further realize the directional adsorption of lithium ions, the active intervention of gas-phase free radicals, the construction of a high-temperature carbonization barrier, and the three-dimensional thermal barrier network configuration, thereby significantly improving the multi-dimensional safety performance of the coating in the battery thermal runaway, salt spray corrosion, and high-temperature impact environments. Its fire reaction response time is shorter, the flame retardant efficiency is higher, and the anti-corrosion ability is more durable, which is significantly better than the existing protective coating system. Description of the Drawings

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0052] Figure 1 It is a schematic diagram of the composition of an anti-corrosion and fire-proof coating for new energy battery boxes proposed by the present invention;

[0053] Figure 2 It is a schematic diagram of the process of a preparation method of an anti-corrosion and fire-proof coating for new energy battery boxes proposed by the present invention. Detailed Embodiments

[0054] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings of the specification.

[0055] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0056] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or selectively exclusive embodiments from other embodiments.

[0057] Embodiment 1:

[0058] Referring to Figure 1 , this is the first embodiment of the present invention. This embodiment provides an anti-corrosion and fire-proof coating applied to a new energy battery box, which includes the following specific components:

[0059] Base resin system, curing agent, functional filler system, flame retardant system, solvent system, and additive system.

[0060] In this embodiment, the specific components are as follows:

[0061] The base resin system uses medium and high molecular weight epoxy resin E44 (or E51), which can firmly adhere to the surfaces of main battery box materials such as aluminum alloy, stainless steel, and phosphated steel plates, can resist the penetration of acids, alkalis, salt spray, and alcohol-based electrolytes, and provides a good dispersion and encapsulation matrix for subsequent flame retardant components and nano additives.

[0062] The curing agent uses a compound curing agent of modified aliphatic amine and phenolic amine to ensure good low-temperature curing performance (rapid curing can be achieved at room temperature / 60°C), has excellent compatibility with flame retardant additives and special functional components, and avoids delamination; provides a three-dimensional network cross-linked structure to improve the overall mechanical strength and thermal stability.

[0063] The functional filler system uses sheet-structured fillers, including mica powder, sheet-shaped aluminum silicate, and glass flakes, to block corrosive media through a "brick wall structure"; inhibits the penetration of water vapor, prevents interfacial corrosion; and improves crack resistance under high temperature or thermal cycling. Further, the selected fillers are all surface-modified (such as treated with silane coupling agent) to enhance the interfacial bonding force with the resin and prevent long-term peeling.

[0064] In the flame retardant system, conventional halogen-containing flame retardants are not used in this system to avoid releasing toxic gases at high temperatures. Instead, environmentally friendly non-halogen flame retardants are selected, including melamine polyphosphate and microencapsulated red phosphorus particles; the two can cooperate to form a thermal shield + self-extinguishing carbon layer, meeting the requirements of UL-94V0 rating.

[0065] The solvent system includes xylene, butanol, and cyclohexanone, which are used to enhance the dissolving power and coating performance, adjust the drying speed, prevent surface drying while internal non-drying, and improve the leveling and adhesion of the film formation. The boiling point gradient design of the solvent is used to optimize the drying rate, taking into account the construction adaptability and coating uniformity.

[0066] The additive system includes a wetting and dispersing agent and an antifoaming agent. In this embodiment, the mass ratio of the wetting and dispersing agent to the antifoaming agent is 5:1. The wetting and dispersing agent uses polyether-modified acrylate molecules to enhance the dispersion of pigments and functional additives and avoid sedimentation; the antifoaming agent uses polyether silicone materials to control the formation of microbubbles and prevent pinholes or coating defects.

[0067] The mass fractions of the specific components are as follows:

[0068] The base resin system is 30 parts;

[0069] The curing agent is 5 parts;

[0070] The functional filler system is 10 parts;

[0071] The flame retardant system is 10 parts;

[0072] The solvent system is 10 parts;

[0073] The additive system is 1 part.

[0074] This anticorrosive and fireproof coating also includes additives, and the specific additives include:

[0075] Functionalized MXene-supported lithium ion adsorbent, metal-organic framework encapsulated quaternary phosphonium salt, polyaryletherketone-coated antimony trioxide nanoparticles, boron and nitrogen co-doped graphene aerogel powder.

[0076] In this embodiment, the mass fractions of the additives are as follows:

[0077] The functionalized MXene-supported lithium ion adsorbent is 1 part;

[0078] The metal-organic framework encapsulated quaternary phosphonium salt is 0.5 part;

[0079] The polyaryletherketone-coated antimony trioxide nanoparticles are 1 part;

[0080] The boron and nitrogen co-doped graphene aerogel powder is 0.5 part.

[0081] In this embodiment, the functionalized MXene-supported lithium ion adsorbent has a Ti3C2Tx-type MXene two-dimensional material as the main body, where Tx is a surface functional group (such as -OH, =O, -F). The MXene surface is grafted with sulfonic acid group -SO3H and carboxyl group -COOH functional groups to improve the affinity with the polar electrolyte, and is loaded with lithium aluminum hydrotalcite-like compound nanoparticles, which have the characteristics of high specific surface area, fast ion exchange rate, and good thermal stability, and are used to adsorb free lithium ions in the electrolyte leakage accident inside the battery box, slowing down the side reactions and the risk of fire.

[0082] This composite can quickly adsorb Li in the leaked electrolyte under the conditions of battery thermal runaway or shell leakage + , preventing it from generating side reactions with the shell or electrical system. At the same time, the MXene two-dimensional layered structure is prone to carbonization and shrinkage at high temperatures, forming a continuous thermal insulation layer, which helps to inhibit the flame spread path.

[0083] Traditional adsorption-type fillers such as SiO2, activated carbon, bentonite, etc. only have physical pore adsorption ability and lack Li + selective adsorption mechanism; this technology realizes higher response speed and stronger runaway control ability through the dual mechanisms of ion selective exchange mechanism + thermal reaction carbonization barrier mechanism working together.

[0084] In this embodiment, the metal-organic framework (MOF)-encapsulated quaternary phosphonium salt includes a ZIF-8-type metal-organic framework and a quaternary phosphonium salt compound encapsulated in the pore structure of this framework; the metal center of the ZIF-8-type metal-organic framework is Zn 2 + , and the ligand is imidazole group; the quaternary phosphonium salt is a tetraphenylphosphonium structure with a sulfonate substituent, including tetraphenylphosphonium sulfonate; the average particle size of the metal-organic framework-encapsulated quaternary phosphonium salt is in the range of 200-500 nm. After heating, it decomposes and releases P-N-based flame retardant gases, and at the same time the MOF skeleton collapses to form porous carbonaceous residues, providing a gas-phase / condensed-phase dual flame retardant barrier.

[0085] When the temperature of this material rises to 200-300 °C, the ZIF-8 skeleton begins to disintegrate, controlling the release of the quaternary phosphonium salt. The quaternary phosphonium salt can release P · and PO · free radicals in the combustion reaction zone, competitively capturing combustion free radicals H · , OH · , realizing gas-phase flame retardant and fire suppression. At the same time, the collapsed skeleton remains a porous carbon structure, further forming a thermal reflection and physical blocking layer. By "encapsulating" the flame retardant through the MOF structure, a responsive controlled release system is constructed to prevent initial migration and the decline of storage stability.

[0086] In this embodiment, the polyaryletherketone-coated antimony trioxide nanoparticles include antimony trioxide (Sb2O3) nanoparticles with a particle size of 80 - 120 nm, and a polyaryletherketone polymer coating layer uniformly coated on their surfaces. The thickness of the polyaryletherketone polymer coating layer is 20 - 30 nm. Polyaryletherketone (PAEK) has a high molecular rigid backbone, a high glass transition temperature (>250 °C), and good aromatic pyrolysis properties. Under high-temperature conditions, the coating layer decomposes to release aromatic free radicals, enhancing the reaction capture effect of Sb2O3 with free radicals and improving the gas-phase flame retardancy efficiency. At the same time, the pyrolytic carbon layer of PAEK forms a dense carbonization barrier on the coating surface, helping to delay heat conduction and oxygen diffusion.

[0087] Different from the traditional inorganic-organic blending method, the thermal-responsive aromatic polymer is first used for interface regulation to achieve the synergistic amplification effect of inorganic oxides and free radical capture materials. Traditional Sb2O3 often has problems such as serious agglomeration, weak interface bonding, and unstable release efficiency in coatings. The present invention guides the distribution and reaction control of Sb2O3 through the thermal-responsive mechanism of high-performance polymers, and has the characteristics of good interface stability, strong dispersibility, and excellent thermal-responsive effect.

[0088] In this embodiment, the boron and nitrogen co-doped graphene aerogel powder includes a three-dimensional porous graphene structure co-doped with a boron source and a nitrogen source. The graphene aerogel is a honeycomb-like spatial network structure. Among them, boron element doping guides the stable formation of a high-temperature carbon skeleton, and nitrogen element doping enhances the gas-phase fire suppression reaction activity.

[0089] Using graphene oxide as a raw material, a three-dimensional graphene aerogel skeleton is prepared by a hydrothermal reduction-freeze drying technique. A boron source (such as boric acid) and a nitrogen source (such as urea, melamine) are introduced into the reduction system for co-doping at the same time, so that the graphene skeleton forms a B–N co-doped structure. The obtained powder has characteristics such as good skeleton flexibility, low thermal conductivity, and high carbonization efficiency.

[0090] B and N heteroatoms guide the formation of a stable oriented carbon structure of the graphene skeleton at high temperatures, improving the heat resistance, carbonization uniformity, and structural integrity of the coating. In addition, the porous structure of the aerogel effectively isolates the heat conduction path, helping to inhibit flame spread.

[0091] Conventional graphene additives are mostly two-dimensional sheet structures and cannot form a spatial carbon skeleton. When N is doped alone, the carbonized layer is loose and the thermal conductivity is relatively high. When B is doped alone, the charge regulation ability is weak. The present invention enhances the carbonization stability and gas-phase fire suppression ability through the B-N synergy, and at the same time improves the adaptability of the flexible structure to the complex geometric surfaces of the box.

[0092] Example Two:

[0093] Refer to Figure 2, which is the second embodiment of the present invention. This embodiment provides a preparation method of an anti-corrosion and fire-proof coating for a new energy battery box, and is prepared based on the anti-corrosion and fire-proof coating described in Embodiment 1, including the following specific steps:

[0094] S1. Pre-dispersion of the basic resin system;

[0095] The purpose of this step is to form a uniform and moderately fluid continuous phase matrix of the basic resin system through mechanical shearing and premixing operations, so as to provide a stable bonding environment for the dispersion and reaction of subsequent functional components. This system is usually a polymer structure with high heat resistance and high adhesion, and its continuous phase matrix will serve as the structural carrier of the entire coating system, determining the film-forming quality and durability of the coating.

[0096] Take a predetermined mass fraction of the basic resin system, and conduct preliminary uniform stirring in a dispersion tank under the condition that the stirring speed is controlled at 600 - 800 rpm for no less than 30 minutes to ensure the stability of the system viscosity and no obvious resin agglomeration phenomenon is observed macroscopically. During the stirring process, the temperature can be appropriately raised to 40 - 50 °C to reduce the system viscosity and enhance the subsequent system fusion ability, forming a transparent or semi-transparent basic dispersion liquid.

[0097] S2. Synergistic pre-adjustment of the additive system and the solvent system;

[0098] The purpose of this step is to adjust the workability, storage stability and wetting and dispersion ability of the coating system by reasonably blending the additive system and the solvent system, and to provide a good rheological basis for subsequent additives and solid phase dispersion. The additive system optimizes the system stability through interface adjustment, defoaming, dispersion, etc., and the solvent system adjusts the construction viscosity and the system volatilization rate.

[0099] Add the predetermined mass fraction of the additive system and the solvent system to the basic resin pre-dispersion liquid obtained in step S1 in proportion, and stir in a high-speed disperser at 1000 rpm for 20 - 30 minutes to fully dissolve and mutually dissolve the two systems, and the appearance of the system is in a low-viscosity homogeneous liquid state. During this period, monitor the foam and dispersion state of the system to avoid excessive reaction of the additives or out-of-control solvent volatilization.

[0100] S3. Addition and stable dispersion of the functional filler system;

[0101] This step introduces the functional filler system, aiming to enhance the anti-corrosion, shielding and electrolyte penetration resistance of the coating. The functional filler system generally includes inorganic flaky materials with high shielding and high specific surface area, and forms a microscopic multi-layer barrier structure through coupling with the resin system to reduce the medium penetration rate.

[0102] Slowly add a predetermined mass fraction of the functional filler system to the homogeneous system obtained in step S2, and continue stirring at a dispersion speed of 1400 - 1600 rpm for 45 minutes to ensure that the filler is fully wetted and evenly dispersed in the system. During this period, shear force can be appropriately applied to break the particle agglomeration state. Observe the system state to confirm that there is no sedimentation tendency of the filler and a stable suspension distribution is formed.

[0103] S4. Composite integration of the flame retardant system;

[0104] The goal of this step is to introduce a conventional flame retardant system to achieve the gas-phase fire suppression and condensed-phase carbonization barrier formation capabilities of the coating material under fire or thermal runaway conditions. This flame retardant system is usually a multi-component composite material, providing primary flame retardant efficiency and a synergistic substrate for subsequent innovative flame retardant functions.

[0105] Slowly add a predetermined mass fraction of the flame retardant system to the composite system obtained in step S3, and continuously stir for 30 minutes while maintaining the dispersion temperature at 40 - 50 °C to ensure that the flame retardant particles are fully distributed in the binder resin phase. After completion, the system should have strong dispersion stability, no obvious particle sedimentation or segregation phenomenon, and the viscosity should be maintained within the range suitable for spraying or roll coating.

[0106] S5. Introduction of functionalized MXene-supported lithium ion adsorbent;

[0107] The purpose of this step is to disperse the functionalized MXene-supported lithium ion adsorbent into the system to endow the coating with the adsorption control function for metal ion leakage in the battery thermal runaway scenario and enhance the high-temperature barrier performance of the system. Its layered structure has strong compatibility with the resin system and has a synergistic carbonization heat barrier effect.

[0108] Slowly put the dried and pretreated functionalized MXene-supported lithium ion adsorbent into the system obtained in step S4, adjust the stirring speed to 1000 rpm, and maintain the stirring time for no less than 40 minutes. Improve its dispersion uniformity through 10 minutes of ultrasonic assistance and prevent the agglomeration of MXene sheets. After this process is completed, the system should exhibit excellent shear stability and uniformity.

[0109] S6. Gradient dispersion of metal-organic framework encapsulated quaternary phosphonium salt;

[0110] The purpose of this step is to introduce metal-organic framework encapsulated quaternary phosphonium salt to achieve a controllable release type of gas-phase flame retardant performance. The MOF structure can release phosphorus-based free radical inhibitors at high temperatures, enhance the flame spread blocking ability, and make up for the delayed reaction defect of the conventional flame retardant system.

[0111] Slowly disperse the metal-organic framework encapsulated quaternary phosphonium salt in the product of step S5, control the dispersion speed at 800 - 1000 rpm, avoid structural damage, stir for 30 minutes to form a uniformly dispersed composite flame retardant system. The system temperature should be controlled not to exceed 45 °C to avoid premature triggering of the MOF thermal response mechanism. Observe the change in system transparency to ensure that no visible aggregates of particles are formed.

[0112] S7. Addition of polyaryletherketone-coated antimony trioxide nanoparticles;

[0113] The purpose of this step is to introduce polyaryletherketone-coated antimony trioxide nanoparticles, whose high-temperature aromatic carbonization performance synergizes with the free radical fire suppression characteristics of antimony trioxide to effectively improve the condensed-phase fire prevention ability of the coating, and take into account stability and halogen-free safety.

[0114] Slowly add polyaryletherketone-coated antimony trioxide nanoparticles to the mixed system obtained in step S6, increase the shear rate to 1600 rpm, and stir for 25 - 35 minutes to ensure that the integrity of the coating structure is not damaged. The stirred system should show a slightly milky appearance but have a uniform particle size distribution, with good construction adaptability.

[0115] S8. Final introduction and stabilization of boron and nitrogen co-doped graphene aerogel powder;

[0116] This step is the final functional filling step, introducing boron and nitrogen co-doped graphene aerogel powder to enhance the overall thermal stability, thermal insulation and carbonization protection performance of the coating. Its three-dimensional structure and multi-functional doping effect build a multi-level microscopic heat insulation barrier, which helps to delay heat conduction in the thermal runaway scenario.

[0117] Slowly add boron and nitrogen co-doped graphene aerogel powder to the composite system obtained in step S7 in batches, stir with high-speed shear (1800 rpm) for 45 minutes, and at the same time assist with low-frequency ultrasonic oscillation for 10 minutes to form a uniformly suspended system. The finally obtained anti-corrosion and fire-proof coating should have good rheology, thermal stability and sedimentation resistance, and is suitable for surface coating applications of various new energy battery box substrates.

[0118] Example three:

[0119] To comprehensively evaluate the performance of the anti-corrosion and fire-proof coating provided by the present invention, according to national standards and industry testing methods, the following multiple performance tests were carried out on the coating samples, including thermal stability test, heat insulation and fire protection test, flame retardant grade evaluation, smoke density grade detection, salt spray corrosion test, adhesion test, damp heat resistance test, thermal shock cycle test, lithium ion adsorption performance test, and quality stability detection.

[0120] In this embodiment, according to the national standards GB 38031-2025 "Safety Requirements for Power Batteries for Electric Vehicles", GB / T 10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test", GB / T 9978-2008 "Test Method for Fire Resistance of Building Elements", GB / T 9286 "Cross-Cut Test Method for Paints", ASTM E84 "Standard Test Method for Surface Burning Characteristics of Building Materials", ASTM E662 "Test Method for Optical Density of Smoke Generated by Materials in Combustion", and UL 94 standard, the following performance tests were carried out on the coating sample:

[0121] Thermal stability test:

[0122] Simulate the heat-receiving scenario of the battery box, and observe the coating state in an environment of 450°C constant temperature for 10 minutes to verify its high-temperature stability.

[0123] Heat insulation and fire protection test:

[0124] Directly irradiate the surface of the coating with a high-temperature flame gun at 1100°C, and measure its heat barrier duration. This test simulates the situation of flame backfire during thermal runaway and evaluates the fire protection durability.

[0125] Flame retardant grade evaluation:

[0126] Evaluate the combustion grade of the material according to the UL 94 vertical burning test, and determine its self-extinguishing ability and flame retardant reaction time.

[0127] Smoke density grade detection:

[0128] Measure the density index of the smoke generated during the combustion of the material to reflect its low-smoke property and environmental adaptability.

[0129] Salt spray corrosion test:

[0130] Evaluate the corrosion resistance of the coating in extreme environments through a 720-hour neutral salt spray corrosion test, which meets the road use environment of the battery box.

[0131] Adhesion test:

[0132] Use the cross-cut method to detect the bonding force of the coating film to the substrate to ensure its reliability under mechanical vibration or impact.

[0133] Moisture and heat resistance performance test:

[0134] Evaluate the stability and anti-peeling ability of the coating in a thermo-humid coupled environment by continuously maintaining it for 240 hours in an environment of 60°C and 98% relative humidity.

[0135] Thermal shock cycle test:

[0136] Perform 50 thermal cycle simulation conditions between -40°C and +120°C to detect the integrity of the coating after thermal expansion and contraction.

[0137] Lithium ion adsorption performance test:

[0138] Evaluate the capture ability of the functionalized MXene adsorbent in the coating for lithium salts (such as LiPF6) through an internal test method, and quantify its ability to prevent leakage and secondary pollution.

[0139] Quality stability detection:

[0140] Use the density method to observe the quality fluctuations of the coating during storage and use to ensure product consistency.

[0141] The above test results are shown in Table 1.

[0142] Table 1 Performance results of the anti-corrosion and fire-proof coating

[0143]

[0144]

[0145] Through comprehensive analysis of the above multiple test results, the anti-corrosion and fire-proof coating performs excellently in aspects such as fire response, heat insulation, anti-corrosion and anti-erosion, and structural stability. Among them, in the high-temperature flame direct burning test at 1100°C, the coating can continuously provide a heat insulation of ≥38 minutes, effectively blocking the conduction of heat to the battery structural components, significantly better than the 20 - 25 minutes level of traditional flame retardant coatings; the lithium ion adsorption efficiency reaches 93.2%, effectively inhibiting the corrosion and risk of secondary thermal reaction caused by electrolyte leakage.

[0146] In addition, no blistering and rusting were observed on the surface of the coating during the 720-hour salt spray corrosion test, and the cross-cut adhesion reached grade 0, indicating that it has good long-term service stability and mechanical adhesion performance. No obvious cracks and delamination were observed in the humidity and heat cycle tests, showing excellent environmental adaptability.

[0147] In summary, the anti-corrosion and fire-proof coating not only meets the basic requirements for the thermal stability and protection performance of electric vehicle battery boxes in GB 38031-2025, but also has significant technical advantages in high-temperature response, ion capture, and environmental compatibility, and can be widely applied to the thermal safety protection field of new energy vehicle power systems.

[0148] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An anti-corrosion and fire-proof coating applied to a new energy battery box, characterized in that, It includes the following specific components: Base resin system, curing agent, functional filler system, flame retardant system, solvent system, additive system; The anti-corrosion and fire-proof coating further includes additives, and the additives specifically include: Functionalized MXene loaded with lithium ion adsorbent, metal-organic framework encapsulated quaternary phosphonium salt, polyaryletherketone coated antimony trioxide nanoparticles, boron and nitrogen co-doped graphene aerogel powder.

2. The anti-corrosion and fire-proof coating for a new energy battery box according to claim 1, wherein Among the specific components: The base resin system uses medium to high molecular weight epoxy resin; The curing agent uses a compound curing agent of modified aliphatic amine and phenolic amine; The functional filler system uses flaky structure fillers, including mica powder, flaky aluminum silicate and glass flakes; The flame retardant system uses an environment-friendly non-halogen flame retardant, including melamine polyphosphate and microencapsulated red phosphorus particles; The solvent system includes xylene, butanol and cyclohexanone; The additive system includes a wetting and dispersing agent and an antifoaming agent.

3. The anti-corrosion and fire-proof coating for a new energy battery box according to claim 1, characterized in that, The mass parts of the specific components are as follows: The base resin system is 30 - 50 parts; The curing agent is 5 - 15 parts; The functional filler system is 10 - 30 parts; The flame retardant system is 10 - 20 parts; The solvent system is 10 - 25 parts; The additive system is 1 - 3 parts.

4. An anti-corrosion and fire-proof coating applied to a new energy battery box according to claim 1, characterized in that, The mass parts of the additives are as follows: The functionalized MXene loaded with lithium ion adsorbent is 1 - 3 parts; The metal-organic framework encapsulated quaternary phosphonium salt is 0.5 - 2.0 parts; The polyaryletherketone coated antimony trioxide nanoparticles are 1 - 2 parts; The boron and nitrogen co-doped graphene aerogel powder is 0.5 - 1.5 parts.

5. An anti-corrosion and fire-proof coating applied to a new energy battery box according to claim 1, characterized in that, The functionalized MXene loaded with lithium ion adsorbent takes the Ti3C2Tx type MXene two-dimensional material as the main body, where Tx is the surface functional group, and the MXene is grafted with sulfonic acid group -SO3H and carboxyl group -COOH functional groups, and is loaded with lithium aluminum hydrotalcite-like compound nanoparticles, which are used to adsorb free lithium ions in the electrolyte leakage accident inside the battery box.

6. The anti-corrosion and fire-proof coating for a new energy battery box according to claim 1, characterized in that, The metal-organic framework encapsulated quaternary phosphonium salt includes a ZIF-8 type metal-organic framework and a quaternary phosphonium salt compound encapsulated in the pore structure of the framework; The metal center of the ZIF-8 type metal-organic framework is Zn 2+ , and the ligand is imidazole-based; The quaternary phosphonium salt has a tetraphenylphosphonium structure with a sulfonate substituent, including tetraphenylphosphonium sulfonate; The average particle size of the metal-organic framework encapsulated quaternary phosphonium salt is in the range of 200 - 500 nm.

7. An anti-corrosion and fire-proof coating applied to a new energy battery box according to claim 1, characterized in that, The polyaryletherketone coated antimony trioxide nanoparticles include antimony trioxide Sb2O3 nanoparticles with a particle size of 80 - 120 nm, and a polyaryletherketone polymer coating layer uniformly coated on the surface thereof, and the thickness of the polyaryletherketone polymer coating layer is 20 - 30 nm; The coating layer decomposes and releases aromatic free radicals, enhancing the reaction capture effect of Sb2O3 with free radicals, and is used to improve the gas-phase flame retardant efficiency.

8. An anti-corrosion and fire-proof coating for a new energy battery box according to claim 1, characterized in that, The boron and nitrogen co-doped graphene aerogel powder includes a three-dimensional porous graphene structure co-doped with a boron source and a nitrogen source, and the graphene aerogel is a honeycomb-like space network structure; among them, boron element doping guides the stable formation of the high-temperature carbon skeleton, and nitrogen element doping enhances the gas-phase fire suppression reaction activity.

9. A preparation method of an anti-corrosion and fire-proof coating for a new energy battery box, which is prepared based on the anti-corrosion and fire-proof coating according to any one of claims 1-8, characterized in that, It includes the following specific steps: S1. Pre-dispersion of the base resin system; S2. Synergistic pre-adjustment of the additive system and the solvent system; S3. Addition and stable dispersion of the functional filler system; S4. Composite integration of the flame retardant system; S5. Introduction of functionalized MXene-loaded lithium ion adsorbent; S6. Gradient dispersion of metal-organic framework encapsulated quaternary phosphonium salts; S7. Addition of polyaryletherketone-coated antimony trioxide nanoparticles; S8. Final introduction and stabilization of boron and nitrogen co-doped graphene aerogel powder.

10. The preparation method of an anti-corrosion and fire-proof coating applied to a new energy battery box according to claim 9, characterized in that, The method also includes performance testing of samples of the prepared anti-corrosion and fire-proof coatings, including thermal stability testing, heat insulation and fire-proof testing, flame retardant grade evaluation, smoke density grade detection, salt spray corrosion testing, adhesion testing, damp heat resistance testing, thermal shock cycle testing, lithium ion adsorption performance testing, and mass stability detection.

Images