A corrosion and fireproof paint applied to a new energy battery box and a preparation method thereof

Abstract

The application discloses a kind of anticorrosive fire-retardant paint applied to new energy battery box and preparation method, it is related to industrial coating technical field, comprising the following specific component ingredients: base resin system, curing agent, functional filler system, fire-retardant system, solvent system, additive system;The anticorrosive fire-retardant paint further includes additive, the additive specifically includes: functionalized MXene load lithium ion adsorbent, metal organic framework encapsulated quaternary phosphonium salt, polyaryletherketone coated antimony trioxide nanoparticles, boron-nitrogen co-doped graphene aerogel powder;And preparation based on above material.The application introduces a variety of additives in traditional base coating system, further realizes lithium ion directional adsorption, gas-phase free radical active intervention, high-temperature carbonization barrier construction and three-dimensional heat barrier network configuration on the basis of having basic fire-retardant and anticorrosion structure, so as to significantly improve the multi-dimensional safety performance of coating in battery thermal runaway, salt spray corrosion and high-temperature impact environment.

Description

Technical Field

[0001] This invention relates to the field of industrial coatings technology, specifically to an anti-corrosion and fireproof coating for use in new energy battery boxes and its preparation method. Background Technology

[0002] With the rapid development of the new energy vehicle industry, power batteries, as their core components, have placed more stringent demands on the corrosion and fire resistance of battery casing structures. Currently, protective coatings widely used in battery casings are mostly based on epoxy, polyurethane, or silicone resins, combined with phosphorus-nitrogen or halogen-substituted flame retardants, achieving certain thermal protection and corrosion inhibition functions through film-forming heat insulation and carbonization barrier mechanisms. However, existing technologies generally suffer from the following shortcomings:

[0003] On the one hand, traditional flame retardant additives such as aluminum hydroxide, phosphate esters, and antimony trioxide have certain flame retardant properties, but their release rate is uncontrollable under actual high-temperature thermal runaway conditions, and the flame retardant reaction response is delayed. This makes it difficult to achieve rapid thermal isolation and gas phase intervention during the thermal runaway process of lithium-ion batteries, which can easily cause flame spread and structural damage.

[0004] On the other hand, existing anti-corrosion systems mostly use sheet-like fillers or surface coatings to establish a barrier layer, which cannot deeply capture metal ions or corrosive byproducts in the electrolyte. As a result, the problems of lithium salt penetration and corrosion accumulation remain prominent during long-term service, especially in high-temperature or electrolyte leakage environments.

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

[0006] To address the shortcomings of existing technologies, this invention provides an anti-corrosion and fire-retardant coating for new energy battery boxes and its preparation method, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides an anti-corrosion and fireproof coating for new energy battery boxes, comprising the following specific components:

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

[0010] The anti-corrosion and fire-retardant coating also includes additives, specifically including:

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

[0012] To further optimize this technical solution, the specific components include:

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

[0014] The curing agent is a compound curing agent of modified aliphatic amines and phenolic amines;

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

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

[0017] Solvent systems include xylene, butanol, and cyclohexanone;

[0018] The additive system includes wetting and dispersing agents and defoamers.

[0019] To further optimize this technical solution, the specific component mass fractions are as follows:

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

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

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

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

[0024] The solvent system consists of 10-25 parts;

[0025] The auxiliary agent system consists of 1-3 parts.

[0026] To further optimize this technical solution, the mass fractions of the additives are as follows:

[0027] Functionalized MXene-supported lithium-ion adsorbent: 1-3 parts;

[0028] The metal-organic framework encapsulates 0.5-2.0 parts of quaternary phosphine salt;

[0029] The amount of polyaryletherketone-coated antimony trioxide nanoparticles is 1-2 parts;

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

[0031] To further optimize this technical solution, the functionalized MXene-loaded lithium-ion adsorbent is based on a 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 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 phosphine salt includes a ZIF-8 type metal-organic framework and a quaternary phosphine salt compound encapsulated within the pore structure of the framework;

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

[0034] The quaternary phosphine salt is a tetraphenylphosphine-type structure with sulfonate substituents, including tetraphenylphosphine sulfonate;

[0035] The average particle size of the metal-organic framework encapsulated quaternary phosphine 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 their surface, wherein the thickness of the polyaryletherketone polymer coating layer is 20-30 nm.

[0037] The coating decomposes and releases aromatic free radicals, enhancing the capture effect of Sb2O3 in the reaction with free radicals, thereby improving the efficiency of gas-phase flame retardancy.

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

[0039] A method for preparing an anti-corrosion and fire-retardant coating for use in new energy battery boxes, based on the above-mentioned anti-corrosion and fire-retardant coating, includes the following specific steps:

[0040] S1, Pre-dispersion of the basic resin system;

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

[0042] S3. The addition and stable dispersion of functional filler system;

[0043] S4, the composite integration of flame retardant systems;

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

[0045] S6. Gradient dispersion of quaternary phosphine salts encapsulated in metal-organic frameworks;

[0046] S7, the addition of polyaryletherketone-coated antimony trioxide nanoparticles;

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

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

[0049] Compared with the prior art, the present invention provides an anti-corrosion and fireproof coating for new energy battery boxes and its preparation method, which has the following beneficial effects:

[0050] This anti-corrosion and fireproof coating for new energy battery boxes and its preparation method, by synergistically introducing multiple additives into the traditional basic coating system, further achieves lithium-ion directional adsorption, active intervention of gas-phase free radicals, high-temperature carbonization barrier construction, and three-dimensional thermal barrier network configuration on the basis of basic flame retardant and anti-corrosion structure. This significantly improves the multi-dimensional safety performance of the coating under battery thermal runaway, salt spray corrosion, and high-temperature shock environments. Its fire-retardant response time is shorter, its flame-retardant efficiency is higher, and its anti-corrosion ability is more durable, which is significantly better than the existing protective coating system. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a schematic diagram illustrating the composition of an anti-corrosion and fire-retardant coating for new energy battery boxes proposed in this invention.

[0053] Figure 2 This is a schematic flowchart illustrating the preparation method of an anti-corrosion and fireproof coating for new energy battery boxes proposed in this invention. Detailed Implementation

[0054] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0055] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0056] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0057] Example 1:

[0058] Reference Figure 1 This is the first embodiment of the present invention, which provides an anti-corrosion and fireproof coating for use in new energy battery boxes, comprising the following specific components:

[0059] Basic 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-to-high molecular weight epoxy resin E44 (or E51), which can firmly adhere to the surface of battery box main materials such as aluminum alloy, stainless steel, and phosphated steel plate. It can resist the penetration of acids, alkalis, salt spray, and alcohol electrolytes, and provide a good dispersion and encapsulation matrix for subsequent flame retardant components and nano-additives.

[0062] The curing agent is a compound curing agent of modified aliphatic amine and phenolic amine, which ensures good low-temperature curing performance (can achieve rapid curing at room temperature / 60℃), excellent compatibility with flame retardant additives and special functional components, and avoids delamination; it provides a three-dimensional network cross-linking structure, which improves the overall mechanical strength and thermal stability.

[0063] The functional filler system employs sheet-like fillers, including mica powder, sheet-like aluminum silicate, and glass flakes, which act as a "brick wall structure" to block corrosive media, inhibit water vapor penetration, prevent interfacial corrosion, and improve crack resistance under high temperature or thermal cycling. Furthermore, all selected fillers undergo surface modification treatment (such as silane coupling agent treatment) to enhance interfacial bonding with the resin and prevent long-term delamination.

[0064] In this flame retardant system, conventional halogenated flame retardants are not used to avoid the release of toxic gases at high temperatures. Instead, environmentally friendly non-halogenated flame retardants are selected, including melamine polyphosphate and microencapsulated red phosphorus particles. The two work together to form a heat shield + self-extinguishing carbon layer, which meets the UL-94V0 rating requirements.

[0065] The solvent system includes xylene, butanol, and cyclohexanone, which are used to enhance solubility and coating performance, regulate drying speed, prevent surface drying but internal incomplete drying, and improve film leveling and adhesion. The solvent boiling point gradient is designed to optimize the drying rate, balancing application adaptability and coating uniformity.

[0066] The additive system includes a wetting and dispersing agent and a defoamer. In this embodiment, the mass ratio of the wetting and dispersing agent to the defoamer is 5:1. The wetting and dispersing agent uses polyether-modified acrylate molecules to improve the dispersibility of pigments and functional additives and prevent sedimentation. The defoamer uses polyether siloxane materials to control microbubble formation and prevent pinholes or coating defects.

[0067] The specific components are described in the following mass fractions:

[0068] The base resin system consists of 30 parts;

[0069] The curing agent consists of 5 parts;

[0070] The functional filler system consists of 10 parts;

[0071] The flame retardant system consists of 10 parts;

[0072] The solvent system consists of 10 parts;

[0073] The auxiliary agent system consists of 1 part.

[0074] The anti-corrosion and fire-retardant coating also includes additives, specifically including:

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

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

[0077] One part of functionalized MXene-supported lithium-ion adsorbent;

[0078] The metal-organic framework encapsulates 0.5 parts of the quaternary phosphine salt;

[0079] One part of polyaryletherketone-coated antimony trioxide nanoparticles;

[0080] The boron-nitrogen co-doped graphene aerogel powder was 0.5 parts.

[0081] In this embodiment, the functionalized MXene-loaded lithium-ion adsorbent is based on a Ti3C2Tx type MXene two-dimensional material, where Tx represents surface functional groups (such as -OH, =O, -F). The MXene surface is grafted with sulfonic acid group -SO3H and carboxyl group -COOH functional groups to improve its affinity with polar electrolytes. It is also loaded with lithium aluminum hydrotalcite compound nanoparticles, which have the characteristics of high specific surface area, fast ion exchange rate and good thermal stability. It is used to adsorb free lithium ions in the event of electrolyte leakage inside the battery box, thereby mitigating side reactions and fire risks.

[0082] This composite can rapidly adsorb Li from leaking electrolyte under conditions of battery thermal runaway or casing leakage. + This prevents it from generating side reactions with the casing or electrical system. Simultaneously, the MXene two-dimensional layered structure readily carbonizes and shrinks at high temperatures, forming a continuous thermal insulation layer that helps suppress the flame spread path.

[0083] Traditional adsorption packing materials such as SiO2, activated carbon, and bentonite only possess physical pore adsorption capabilities and lack Li + Selective adsorption mechanism: This technology achieves higher response speed and stronger runaway control capability through the synergistic effect of ion selective exchange mechanism and thermal reaction carbonization barrier mechanism.

[0084] In this embodiment, the metal-organic framework (MOF) encapsulating the quaternary phosphine salt comprises a ZIF-8 type metal-organic framework and a quaternary phosphine salt compound encapsulated within the pore structure of the framework; the metal center of the ZIF-8 type metal-organic framework is Zn. 2 + The ligand is an imidazole group; the quaternary phosphine salt is a tetraphenylphosphine-type structure with sulfonate substituents, including tetraphenylphosphine sulfonate; the average particle size of the quaternary phosphine salt encapsulated by the metal-organic framework is in the range of 200-500 nm. Upon heating, it decomposes and releases PN-based flame-retardant gas, while the MOF framework collapses to form porous carbonaceous residue, providing a dual flame-retardant barrier in both the gas and condensed phases.

[0085] When the temperature rises to 200-300℃, the ZIF-8 framework of this material begins to disintegrate, releasing quaternary phosphine salts in a controlled manner. These quaternary phosphine salts can release phosphorus (P) in the combustion reaction zone. · With PO · Free radicals, competitively capturing and burning free radicals H · OH · This achieves gas-phase flame retardancy and fire suppression, while the collapsed skeleton retains a porous carbon structure that further forms a heat-reflective and physical barrier layer. By encapsulating the flame retardant through the MOF structure, a responsive controlled-release system is constructed to prevent initial migration and decreased storage stability.

[0086] In this embodiment, the polyaryletherketone (PAEK)-coated antimony trioxide (Sb₂O₃) nanoparticles comprise antimony trioxide (Sb₂O₃) nanoparticles with a particle size of 80-120 nm, and a PAEK polymer coating layer uniformly coated on their surface, the thickness of which is 20-30 nm. PAEK possesses a rigid polymer framework, a high glass transition temperature (>250°C), and good aromatic pyrolysis properties. Under high-temperature conditions, the coating layer decomposes and releases aromatic free radicals, enhancing the Sb₂O₃-free radical reaction capture effect, thereby improving gas-phase flame retardant efficiency. Simultaneously, the PAEK pyrolysis char layer forms a dense carbonization barrier on the coating surface, helping to delay thermal conductivity and oxygen diffusion.

[0087] Unlike traditional inorganic-organic blending methods, this invention is the first to employ thermally responsive aromatic polymers for interface regulation, achieving a synergistic amplification effect between inorganic oxides and free radical scavenging materials. Traditional Sb₂O₃ in coatings often suffers from severe agglomeration, weak interfacial bonding, and unstable release efficiency. This invention guides the distribution and reaction control of Sb₂O₃ through the thermal response mechanism of high-performance polymers, exhibiting characteristics such as good interfacial stability, strong dispersibility, and excellent thermal response.

[0088] In this embodiment, the boron-nitrogen co-doped graphene aerogel powder comprises a three-dimensional porous graphene structure co-doped with boron and nitrogen sources, and the graphene aerogel has a honeycomb spatial network structure; wherein boron doping guides the stable formation of a high-temperature carbon framework, and nitrogen doping enhances the gas-phase fire suppression reaction activity.

[0089] A three-dimensional graphene aerogel framework was prepared using graphene oxide as raw material via hydrothermal reduction-freeze-drying technology. Boron sources (such as boric acid) and nitrogen sources (such as urea and melamine) were introduced into the reduction system for simultaneous doping, resulting in a B–N co-doped structure for the graphene framework. The resulting powder exhibits good framework flexibility, low thermal conductivity, and high carbonization efficiency.

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

[0091] Conventional graphene additives are mostly two-dimensional sheet structures, unable to form a spatial carbon framework; when N doping is present alone, the carbonized layer is loose and has high thermal conductivity, while B doping alone results in weak charge regulation capability. This invention enhances carbonization stability and gas-phase fire suppression capability through the synergistic effect of B and N, while improving the adaptability of the flexible structure to complex box geometry.

[0092] Example 2:

[0093] Reference Figure 2This is the second embodiment of the present invention, which provides a method for preparing an anti-corrosion and fireproof coating for use in new energy battery boxes. The method is based on the anti-corrosion and fireproof coating described in Embodiment 1 and includes the following specific steps:

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

[0095] The purpose of this step is to form a uniform, moderately fluid, continuous phase matrix from the base resin system through mechanical shearing and premixing, providing a stable bonding environment for the dispersion and reaction of subsequent functional components. This system is typically 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 quality and durability of the coating.

[0096] Take a predetermined mass fraction of the base resin system and perform initial uniform stirring in a dispersion tank at a stirring speed controlled at 600-800 rpm for at least 30 minutes to ensure stable system viscosity and no obvious resin agglomeration observed macroscopically. During the stirring process, the temperature can be appropriately increased to 40-50℃ to reduce the system viscosity, enhance the subsequent fusion ability of the system, and form a transparent or semi-transparent base dispersion.

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

[0098] This step aims to adjust the workability, storage stability, and wetting and dispersing capabilities of the coating system by rationally blending the additive and solvent systems, thus providing a good rheological basis for the subsequent dispersion of additives and the solid phase. The additive system optimizes system stability through interface regulation, defoaming, and dispersion, while the solvent system adjusts the application viscosity and system evaporation rate.

[0099] Add the predetermined mass fractions of the additive system and solvent system to the pre-dispersion liquid of the base resin obtained in step S1 in a specific ratio, and stir at 1000 rpm for 20-30 minutes in a high-speed disperser to ensure that the two systems are fully dissolved and miscible, and the system appears as a low-viscosity homogeneous liquid. Monitor the foam and dispersion state of the system during this process to avoid excessive reaction of the additives or uncontrolled evaporation of the solvent.

[0100] S3. The addition and stable dispersion of functional filler system;

[0101] This step introduces a functional filler system to enhance the coating's corrosion resistance, shielding properties, and resistance to electrolyte penetration. The functional filler system typically comprises inorganic sheet-like materials with high shielding properties and high specific surface area, which, through coupling with the resin system, form a microscopic multilayer barrier structure, reducing the medium penetration rate.

[0102] Slowly add the 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 uniformly dispersed in the system. During this process, appropriate shear force can be applied to break particle aggregation. Observe the system state to confirm that the filler shows no tendency to settle and forms a stable suspension distribution.

[0103] S4, the composite integration of flame retardant systems;

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

[0105] Slowly add the predetermined mass fraction of the flame-retardant system to the composite system obtained in step S3, and continue stirring for 30 minutes while maintaining the dispersion temperature at 40-50℃ to ensure that the flame-retardant particles are fully distributed in the binder resin phase. The completed system should exhibit strong dispersion stability, with no obvious particle sedimentation or segregation, and the viscosity should remain within a range suitable for spraying or roller coating.

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

[0107] This step aims to disperse functionalized MXene-loaded lithium-ion adsorbents into the system, thereby endowing the coating with adsorption and control functions for metal ion leakage under battery thermal runaway scenarios and enhancing the system's high-temperature barrier performance. Its layered structure exhibits strong compatibility with the resin system and provides a synergistic carbonization thermal barrier effect.

[0108] The pre-treated functionalized MXene-loaded lithium-ion adsorbent was slowly added to the system obtained in step S4, and the stirring speed was adjusted to 1000 rpm, maintaining the stirring time for at least 40 minutes. Ultrasonication was then used for 10 minutes to improve dispersion uniformity and prevent MXene sheet aggregation. After this process, the system should exhibit excellent shear stability and uniformity.

[0109] S6. Gradient dispersion of quaternary phosphine salts encapsulated in metal-organic frameworks;

[0110] The purpose of this step is to introduce a metal-organic framework (MOF) to encapsulate the quaternary phosphine salt to achieve controlled-release gas-phase flame retardant properties. The MOF structure can release phosphorus-based free radical inhibitors at high temperatures, enhancing flame spread blocking capabilities and compensating for the delayed reaction defects of conventional flame retardant systems.

[0111] Slowly disperse the metal-organic framework-encapsulated quaternary phosphine salt into the product of step S5, controlling the dispersion speed at 800-1000 rpm to avoid structural damage. Stir for 30 minutes to form a uniformly dispersed composite flame-retardant system. The system temperature should be controlled to not 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 form.

[0112] S7, the addition of polyaryletherketone-coated antimony trioxide nanoparticles;

[0113] The purpose of this step is to introduce polyaryletherketone (PAE) to coat antimony trioxide nanoparticles. The high-temperature aromatic carbonization performance of PAE, combined with the free radical fire suppression properties of antimony trioxide, effectively enhances the condensed phase fire resistance of the coating, while also ensuring stability and halogen-free safety.

[0114] Slowly add polyaryletherketone-coated antimony trioxide nanoparticles to the mixture 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 be slightly emulsified but with a uniform particle size distribution, exhibiting good application adaptability.

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

[0116] This step is the final functional filling step, introducing boron-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 multifunctional doping effect construct a multi-level microscopic thermal barrier, which helps to delay heat conduction in thermal runaway scenarios.

[0117] The boron-nitrogen co-doped graphene aerogel powder was slowly added in batches to the composite system obtained in step S7. The mixture was stirred at high speed (1800 rpm) for 45 minutes, followed by low-frequency ultrasonic vibration for 10 minutes to form a uniform suspension system. The resulting anti-corrosion and fire-retardant coating should possess good rheological properties, thermal stability, and sedimentation resistance, making it suitable for surface coating applications on various new energy battery box substrates.

[0118] Example 3:

[0119] To comprehensively evaluate the performance of the anti-corrosion and fireproof coating provided by this invention, the coating samples were subjected to the following performance tests in accordance with national standards and industry testing methods: thermal stability test, heat insulation and fireproof test, flame retardant rating assessment, smoke density rating detection, salt spray corrosion test, adhesion test, damp heat resistance test, thermal shock cycle test, lithium ion adsorption performance test, and quality stability test.

[0120] In this embodiment, based on 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 "Fire Resistance Test Method for Building Components", GB / T 9286 "Cross-cut Test Method for Paint Films", ASTM E84 "Standard Method for Testing the Burning Characteristics of Building Materials", ASTM E662 "Method for Testing the Optical Smoke Density of Combustion Materials", and UL 94 standard, the following performance tests were conducted on the coating sample:

[0121] Thermal stability test:

[0122] The coating was observed under simulated battery casing heating conditions for 10 minutes at a constant temperature of 450℃ to verify its high-temperature stability.

[0123] Thermal insulation and fire resistance test:

[0124] The coating surface was directly irradiated with a high-temperature flame gun at 1100℃, and the duration of its thermal barrier effect was measured. This test simulates the flame backfire scenario during thermal runaway to evaluate fire resistance durability.

[0125] Flame retardancy rating assessment:

[0126] The material's flammability rating is assessed based on the UL 94 vertical burning test to determine its self-extinguishing ability and flame-retardant reaction time.

[0127] Smoke density level testing:

[0128] The density index of smoke produced during the combustion of materials is measured to reflect their low smoke content and environmental adaptability.

[0129] Salt spray corrosion test:

[0130] The coating's corrosion resistance in extreme environments was evaluated through a 720-hour neutral salt spray corrosion test, ensuring it meets the requirements for road use of battery boxes.

[0131] Adhesion test:

[0132] The cross-cut test is used to test the adhesion of the coating to the substrate to ensure its reliability under mechanical vibration or impact.

[0133] Moisture and heat resistance test:

[0134] The stability and anti-peeling ability of the coating were evaluated by continuously operating the coating at 60°C and 98% relative humidity for 240 hours in a thermal-humidity coupled environment.

[0135] Thermal shock cycling test:

[0136] The coating was subjected to 50 thermal cycling simulations between -40℃ and +120℃ to test its integrity after thermal expansion and contraction.

[0137] Lithium-ion adsorption performance test:

[0138] The ability of functionalized MXene adsorbents in coatings to capture lithium salts (such as LiPF6) was evaluated using internal testing methods, quantifying their ability to prevent secondary pollution from leaks.

[0139] Quality stability testing:

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

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

[0142] Table 1 Performance Results of Anti-corrosion and Fireproof Coatings

[0143]

[0144]

[0145] Based on a comprehensive analysis of the above test results, this anti-corrosion and fire-retardant coating demonstrates excellent performance in fire response, thermal barrier, corrosion resistance, and structural stability. Specifically, in a direct flame test at 1100℃, the coating provides continuous thermal barrier for ≥38 minutes, effectively blocking heat conduction to battery structural components, significantly better than the 20-25 minutes achieved by traditional flame-retardant coatings. The lithium-ion adsorption efficiency reaches 93.2%, effectively suppressing the risk of corrosion and secondary thermal reactions caused by electrolyte leakage.

[0146] Furthermore, no blistering or rust was observed on the coating surface during the 720-hour salt spray corrosion test, and the cross-cut adhesion reached level 0, indicating that it possesses good long-term service stability and mechanical adhesion performance. No obvious cracks or delamination were observed during damp heat and thermal cycling tests, demonstrating excellent environmental adaptability.

[0147] In summary, this anti-corrosion and fireproof coating not only meets the basic requirements for 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 used in the field of thermal safety protection 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 are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A corrosion-resistant and fire-retardant coating for use in new energy battery boxes, characterized in that, It includes the following specific components: Basic resin system, curing agent, functional filler system, flame retardant system, solvent system, and additive system; The anti-corrosion and fire-retardant coating also includes additives, said additives including: Functionalized MXene-loaded lithium-ion adsorbent, metal-organic framework-encapsulated quaternary phosphine salt, polyaryletherketone-coated antimony trioxide nanoparticles, and boron-nitrogen co-doped graphene aerogel powder; The mass fractions of the additives are as follows: Functionalized MXene-supported lithium-ion adsorbent: 1-3 parts; The metal-organic framework encapsulates 0.5-2.0 parts of quaternary phosphine salt; The amount of polyaryletherketone-coated antimony trioxide nanoparticles is 1-2 parts; The amount of boron-nitrogen co-doped graphene aerogel powder is 0.5-1.5 parts.

2. The anti-corrosion and fireproof coating for new energy battery boxes according to claim 1, characterized in that, Among the specific components: The base resin system uses medium to high molecular weight epoxy resin; The curing agent is a compound curing agent of modified aliphatic amines and phenolic amines; The functional filler system uses sheet-like fillers, including mica powder, sheet-like aluminum silicate, and glass flakes; The flame retardant system uses environmentally friendly non-halogenated flame retardants, including melamine polyphosphate and microencapsulated red phosphorus particles; Solvent systems include xylene, butanol, and cyclohexanone; The additive system includes wetting and dispersing agents and defoamers.

3. The anti-corrosion and fireproof coating for new energy battery boxes according to claim 1, characterized in that, The specific components are described in the following mass fractions: The base resin system consists of 30-50 parts; The curing agent is 5-15 parts; The functional filler system consists of 10-30 parts; The flame retardant system consists of 10-20 parts; The solvent system consists of 10-25 parts; The auxiliary agent system consists of 1-3 parts; The amount of boron-nitrogen co-doped graphene aerogel powder is 0.5-1.5 parts.

4. The anti-corrosion and fireproof coating for new energy battery boxes according to claim 1, characterized in that, The functionalized MXene-loaded lithium-ion adsorbent is based on Ti3C2Tx type MXene two-dimensional material, where Tx is a surface functional group. The surface of the functionalized MXene-loaded lithium-ion adsorbent is grafted with sulfonic acid group -SO3H and carboxyl group -COOH functional groups, and loaded with lithium aluminum hydrotalcite compound nanoparticles, which are used to adsorb free lithium ions in the event of electrolyte leakage inside the battery box.

5. The anti-corrosion and fireproof coating for new energy battery boxes according to claim 1, characterized in that, The metal-organic framework encapsulated quaternary phosphine salt includes a ZIF-8 type metal-organic framework and a quaternary phosphine salt compound encapsulated within the pore structure of the framework; The metal center of the ZIF-8 type metal-organic framework is Zn. 2+ The ligand is an imidazole group; The quaternary phosphine salt is a tetraphenylphosphine-type structure with sulfonate substituents, including tetraphenylphosphine sulfonate; The average particle size of the metal-organic framework encapsulated quaternary phosphine salt is in the range of 200-500 nm.

6. The anti-corrosion and fireproof coating for new energy battery boxes 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 their surface, wherein the thickness of the polyaryletherketone polymer coating layer is 20-30 nm. The coating decomposes and releases aromatic free radicals, enhancing the capture effect of Sb2O3 in the reaction with free radicals, thereby improving the efficiency of gas-phase flame retardancy.

7. The anti-corrosion and fireproof coating for new energy battery boxes according to claim 1, characterized in that, The boron-nitrogen co-doped graphene aerogel powder comprises a three-dimensional porous graphene structure co-doped with boron and nitrogen sources, and the graphene aerogel has a honeycomb spatial network structure; wherein boron doping guides the stable formation of a high-temperature carbon framework, and nitrogen doping enhances the gas-phase fire suppression reaction activity.

8. A method for preparing an anti-corrosion and fire-retardant coating for use in new energy battery boxes, comprising preparing the coating based on any one of claims 1-7, characterized in that, The specific steps include the following: S1, Pre-dispersion of the basic resin system; S2, Synergistic pre-adjustment of the additive system and solvent system; S3. The addition and stable dispersion of functional filler system; S4, the composite integration of flame retardant systems; S5. Introduction of functionalized MXene-supported lithium-ion adsorbent; S6. Gradient dispersion of quaternary phosphine salts encapsulated in metal-organic frameworks; S7, the addition of polyaryletherketone-coated antimony trioxide nanoparticles; S8, the final introduction and stabilization of boron-nitrogen co-doped graphene aerogel powder.

9. A method for preparing an anti-corrosion and fireproof coating for a new energy battery box according to claim 8, characterized in that, The method also includes performance testing of the prepared anti-corrosion and fireproof coating samples, including thermal stability testing, heat insulation and fireproofing testing, flame retardant rating evaluation, smoke density rating detection, salt spray corrosion testing, adhesion testing, damp heat resistance testing, thermal shock cycling testing, lithium ion adsorption performance testing, and quality stability testing.

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