Super fast-charging liquid-cooled cable and preparation method thereof

Abstract

The invention discloses a super fast-charging liquid-cooled cable and a preparation method thereof, belongs to the technical field of cable preparation, and is used for solving the technical problem that the flame retardant property and electromagnetic shielding property of a liquid-cooled cable in the prior art need to be further improved. Meanwhile, node bridging is introduced between the fibers to form a stable network skeleton structure, in a flame-retardant system, a phosphorus-nitrogen synergistic mechanism is adopted to promote rapid generation of a compact carbon layer, invasion of heat and flame is further blocked, and the three aspects cooperate with each other, so that the material can keep structural integrity in a heated environment, and the flame-retardant performance of the material is improved. The heat resistance, the flame retardance and the overall stability are remarkably improved, and the comprehensive protection effect superior to that of a conventional system is shown.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing technology, specifically to a super-fast charging liquid-cooled cable and its manufacturing method. Background Technology

[0002] In the context of super-fast charging, cables need to cope with multiple challenges brought by high current, high voltage and high frequency pulses. First, high current will cause the cable to heat up rapidly in a short time. If the flame retardant performance is insufficient, local overheating or arcing may cause fire risk. Therefore, cable materials must have excellent flame retardancy and be able to form a stable protective layer at high temperatures to delay the spread of flames and reduce the release of harmful gases, thus ensuring the safety of the use environment.

[0003] As fast charging power increases, the electromagnetic radiation problem of cables becomes more prominent. Excessive electromagnetic leakage can not only interfere with surrounding electronic devices, but may also affect the vehicle's own control and communication systems. Therefore, cables need to have excellent electromagnetic shielding capabilities. Multi-layer conductive shielding structures can effectively suppress electromagnetic wave leakage and ensure the electrical compatibility of the system. The combination of flame retardancy and shielding has become the key technical foundation for the reliable operation of liquid-cooled fast charging cables.

[0004] Currently, common liquid-cooled fast charging cables still have some shortcomings in their manufacturing process. First, the flame-retardant system often relies on a single flame retardant, which can only delay the flame when subjected to high current and high temperature impacts, making it difficult to form a dense and stable protective layer, resulting in less than ideal overall heat resistance and flame-retardant performance. Second, the fiber-reinforced materials suffer from insufficient interfacial bonding during processing, making them prone to delamination and cracking when heated or stressed, affecting structural stability. Third, electromagnetic shielding typically uses a single layer or simple braiding method, which has limited shielding effectiveness when facing high-frequency pulses and complex electromagnetic environments, and may still result in signal interference or energy leakage. These shortcomings mean that there is still room for improvement in the safety, reliability, and electrical compatibility of the cables. Summary of the Invention

[0005] The purpose of this invention is to provide a super-fast charging liquid-cooled cable and its preparation method, which solves the technical problem that the flame retardant performance and electromagnetic shielding performance of liquid-cooled cables in the prior art need to be further improved.

[0006] The objective of this invention can be achieved through the following technical solution: a method for preparing a super-fast charging liquid-cooled cable, comprising the following steps:

[0007] S1. A cable core is obtained by twisting together several copper wires with a polyvinyl chloride insulation layer on their surface.

[0008] S2. A shielding layer is obtained by wrapping the cable core with modified fiber cloth;

[0009] S3. Several heat exchange tubes are spirally arranged on the surface of the shielding layer to obtain the heat exchange layer;

[0010] S4. Butene / ethylene / styrene copolymer, flame-retardant microcapsules and excipients are melt-extruded and coated onto the surface of the heat exchange layer. After curing, a sheath layer is obtained, thus obtaining a liquid-cooled cable.

[0011] The method for preparing the modified fiber cloth includes the following steps:

[0012] A1. Annealed copper wire and composite glass fiber yarn are fed into a weaving machine for interlacing weaving, controlling the weaving coverage to be 85-95%, the tension to be maintained at 0.2-0.4N, and the linear speed to be controlled at 10-20m / min, to obtain the modified fiber cloth precursor.

[0013] A2. Apply the conductive and thermally conductive colloid to the nodes of the modified fiber cloth precursor with a thickness of 100-120μm. During the application process, only the nodes are treated without covering the entire surface. The modified fiber cloth is then obtained through post-processing.

[0014] The principle for preparing modified fiber cloth is as follows:

[0015] Annealed copper wire possesses excellent electrical and thermal conductivity, while composite glass fiber yarn exhibits good mechanical strength and thermal stability. Through interlacing, the two materials form a stable interpenetrating network on a macroscopic scale: the copper wire is responsible for constructing continuous electrical / thermal conduction pathways, while the glass fiber yarn provides skeletal support and resistance to deformation, thus achieving a dual balance between structure and performance.

[0016] Secondly, the dotted coating of the conductive and thermally conductive colloid at the node locations is key to the entire modification mechanism. The colloidal system contains active functional groups, which can undergo condensation or hydrogen bonding with active sites such as silanol groups on the glass fiber surface during heat treatment. At the same time, it can combine with the copper wire surface through physical adsorption or interfacial wetting. The colloid forms a "bridging layer" at the microscopic level, which not only enhances the bonding force at the fiber interlacing points, but also endows the node with excellent electrical and thermal conductivity.

[0017] During the curing process, the groups in the colloid undergo a cross-linking reaction, generating a stable three-dimensional network structure. This structure effectively fixes the woven network, preventing nodes from loosening or slipping; on the other hand, the cross-linked conductive filler forms a continuous conductive / thermal pathway within the colloid, thereby ensuring the overall high conductivity of the fiber cloth, ultimately resulting in a modified fiber cloth.

[0018] Furthermore, in step A1, the number of strands in the annealed copper wire is 16-24, and the number of strands in the composite glass fiber yarn is 8-12, wherein the diameter of the copper wire is 0.12-0.18 mm;

[0019] Furthermore, in step A2, the post-treatment includes: after the dot coating is completed, the material is pre-cured at 120-140℃ for 5-8 minutes, and then shaped and cured at 150-160℃ for 10-15 minutes to obtain the modified fiber cloth.

[0020] Furthermore, in step S1, the diameter of the copper wire is 0.5 mm, and the coating thickness of the polyvinyl fluoride is 0.7 mm.

[0021] Furthermore, in step S3, the heat exchange tube is a copper heat exchange tube with an outer diameter of 8 mm and a wall thickness of 0.5 mm. The heat exchange fluid is obtained by mixing deionized water, ethylene glycol and methylbenzotriazole in a ratio of 7 mL:3 mL:0.01 g, and the flow rate is 1.2 m / s.

[0022] Further, in step S4, the melt extrusion operation involves adding the butene / ethylene / styrene copolymer, flame-retardant microcapsules, and excipients into a twin-screw extruder. The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures sequentially set at 150°C, 155°C, 155°C, 160°C, 170°C, 175°C, 180°C, and 185°C. The main motor speed of the twin-screw extruder is 80-120 rpm, and the pressure is 100-150 bar. r, melt extruded and coated onto the surface of the shielding layer, cured and demolded to obtain a sheath layer with a thickness of 1.5 mm. The ratio of butene / ethylene / styrene copolymer, flame retardant microcapsules and excipients is 40-45 g: 15-25 g: 72-100 g. The excipients include the following raw materials in parts by weight: 25-35 parts ethylene-vinyl acetate copolymer, 8-10 parts maleic anhydride grafted SEBS-g-MAH, 35-50 parts aluminum hydroxide, 2 parts lubricant and 2-3 parts antioxidant.

[0023] The reaction principle for preparing the sheath layer is as follows: the flame retardant is uniformly dispersed and stably anchored in the polymer matrix through interfacial chemical action. In this system, the introduced maleic anhydride-grafted SEBS (SEBS-g-MAH) not only acts as a compatibilizer, but also enhances the bond between the microcapsules and the matrix through a specific chemical reaction mechanism.

[0024] First, the flame-retardant microcapsules contain active oxazoline groups on their surface. This structure readily undergoes ring-opening under melt processing conditions, exposing reactive sites such as hydroxyl or amine groups. Simultaneously, the maleic anhydride groups on the SEBS-g-MAH molecular chain can also undergo ring-opening under the same conditions, forming an active carboxyl structure. When the two come into contact, a mutual ring-opening and acylation reaction occurs, thereby generating stable amide or ester bonds. This chemical bonding allows the microcapsules to be firmly locked onto the SEBS molecular chain.

[0025] Secondly, the main segments of SEBS have good compatibility with polyolefin matrices and can form a continuous phase with the matrix through chain entanglement. Therefore, SEBS-g-MAH acts as a bifunctional bridge in the system: one end achieves chemical bonding with the microcapsules through anhydride-oxazoline reaction, while the other end relies on nonpolar segments to tightly bind with the matrix. As a result, the microcapsules are uniformly and stably dispersed inside the sheath layer, avoiding aggregation and migration.

[0026] Finally, this robust interfacial bonding not only ensures that the flame-retardant components can be uniformly released and form a continuous and dense char layer when heated, but also improves the overall structural stability and mechanical properties of the sheath layer, thereby giving the sheath layer excellent flame-retardant effect and long-term service performance.

[0027] Furthermore, the lubricant is one or both of calcium stearate or zinc stearate; the antioxidant is one or both of N,N'-diphenyl-p-phenylenediamine and dioctadecyl thiodipropionate.

[0028] Furthermore, the preparation method of the conductive and thermally conductive colloid includes the following steps:

[0029] B1. Add aminopropyltriethoxysilane, silver nitrate, polyvinylpyrrolidone, and deionized water to a reaction vessel, stir, and add ammonia dropwise. After the addition is completed within 15-20 minutes, add glucose and Ti3C2T. x The dispersion was stirred at room temperature for 30-40 minutes, and then post-processed to obtain Ag-MX composite powder.

[0030] B2. Add Ag-MX composite powder, dipropylene glycol methyl ether, bisphenol A diglycidyl ether, m-xylenediamine and vinyl-terminated polydimethylsiloxane to a reactor and stir. After adding the calculated amount of polymethylhydrosiloxane and Karstedt platinum catalyst, raise the reactor temperature to 80-90℃ and keep it at that temperature for 20-30 min. Then raise the temperature to 120-140℃ and keep it at that temperature for 40-60 min. The post-treatment yields a conductive and thermally conductive colloid.

[0031] The reaction principle for preparing conductive and thermally conductive colloids is as follows:

[0032] Based on the dual mechanism of metal-two-dimensional material composite and organosilicon cross-linking curing, firstly, the organosilicon coupling properties of aminopropyltriethoxysilane are utilized in an aqueous system to achieve stable dispersion and controlled reduction of the silver nitrate precursor in conjunction with the dispersion and complexation effects of polyvinylpyrrolidone. Ammonia water, as an alkaline regulator, promotes the reduction of Ag... + The gradual restoration also helps in the Ti3C2T x Uniform nucleation sites are formed on the surface. Subsequently, glucose further reduces silver ions under mild conditions to generate silver nanoparticles, which are then in situ loaded onto Ti3C2T.x On the surface, a tightly bonded Ag-MX composite powder was obtained. This composite combines the excellent electrical conductivity of metal nanoparticles with the high in-plane thermal conductivity of MXene, thus constructing a continuous and efficient electro-thermal transport channel.

[0033] In the organic phase system, Ag-MX composite powder is introduced into the epoxy resin and organosilicon system. Bisphenol A diglycidyl ether and m-xylenediamine form a cross-linked network through ring-opening reaction, while vinyl-terminated polydimethylsiloxane undergoes addition cross-linking with polymethylhydrosiloxane under the action of Karstedt platinum catalyst. During the entire reaction process, the addition of silicon-hydrogen bonds and vinyl bonds not only endows the material with flexibility and thermal stability, but also firmly embeds the inorganic Ag-MX composite into the three-dimensional cross-linked network of organosilicon-epoxy.

[0034] Through this series of in-situ reduction, interfacial coupling and organosilicon cross-linking curing reactions, a conductive and thermally conductive colloid with both high electrical conductivity and high thermal conductivity is finally formed.

[0035] Furthermore, in step B1, the ammonia concentration is 1 mol / L, and the following ingredients are present: aminopropyltriethoxysilane, silver nitrate, polyvinylpyrrolidone, deionized water, ammonia, glucose, and Ti3C2T. x The dispersion dosage ratio is 1.2g:0.5-0.7g:0.6g:60mL:15mL:1.1-2.2g:100mL, wherein Ti3C2T x The dispersion is composed of Ti3C2T x It is prepared by mixing with deionized water at a ratio of 1-2g:100mL. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake 3-5 times with anhydrous ethanol and deionized water, transfer the filter cake to a drying oven at 80℃, and vacuum dry it to constant weight to obtain Ag-MX composite powder.

[0036] Further, in step B2, the ratio of Ag-MX composite powder, dipropylene glycol methyl ether, bisphenol A diglycidyl ether, m-xylenediamine, vinyl-terminated polydimethylsiloxane, and Karstedt platinum catalyst is 1-2g:0.3g:8-10g:2-3g:2-3g:0.01g, wherein the molar amount of silanol groups in the added polymethylhydrosiloxane is 1.2-1.3 times the molar amount of vinyl groups in the reaction system. The post-treatment includes: after the reaction, allowing the reactor temperature to drop to room temperature, vacuum degassing under a pressure of -0.08MPa for 10-20 minutes, and then fine-tuning the system viscosity using dipropylene glycol methyl ether to achieve a viscosity of 25°C for 10 seconds. -1 After the apparent viscosity is 20-30 Pa·s at the shear rate, it is passed through a 100-mesh sieve to obtain a conductive and thermally conductive colloid.

[0037] Furthermore, the preparation method of the composite glass fiber yarn includes the following steps:

[0038] C1. Add hexagonal boron nitride sheets, Tris buffer and dopamine hydrochloride to the reaction vessel, stir gently at room temperature for 2-4 hours, and then process to obtain PDA-BN powder.

[0039] C2. Add 3-glycidoxypropyltrimethoxysilane, tetraethoxysilane, deionized water and anhydrous ethanol to a reaction vessel, add glacial acetic acid to adjust the pH of the reaction system to 4-5, and age at 40℃ for 1-2 hours to obtain silane sol. Then add PDA-BN powder and 1,3-bis(1-isocyano-2-propyl)benzene to the silane sol to obtain composite sol. Then impregnate glass fiber yarn into the composite sol for 1-2 minutes, and post-process to obtain composite glass fiber yarn.

[0040] The reaction principle for preparing composite glass fiber yarn is as follows:

[0041] Based on the dual effects of interfacial chemical modification and organic / inorganic synergistic crosslinking, firstly, hexagonal boron nitride (BN) forms a polydopamine (PDA) coating layer on its surface through a dopamine self-polymerization reaction. This process relies on the oxidative polymerization characteristics of dopamine molecules in a weakly alkaline buffer environment, which can deposit a coating rich in active groups such as catechol groups and amino groups on the BN surface. This PDA layer not only improves the water dispersibility of BN, but also endows it with good surface reactivity, providing interfacial anchoring sites for subsequent chemical bonding with organosilicon networks and isocyanates.

[0042] Subsequently, under acid catalysis, a silica sol system containing abundant Si-OH and Si-O-Si bonds is generated through the hydrolysis-condensation reaction of 3-glycidoxypropyltrimethoxysilane and tetraethoxysilane. This sol has high reactivity and good film-forming properties. When PDA-BN is introduced into it, the functional groups on the PDA surface undergo condensation or hydrogen bonding with the silanol groups, thereby forming a stable chemical bridge between the BN particles and the inorganic silicon network.

[0043] Furthermore, the introduced 1,3-bis(1-isocyano-2-propyl)benzene can undergo an addition reaction with the amino and hydroxyl groups on the PDA surface to generate urea bonds or urethane bonds. This reaction not only enhances the bonding strength between BN and the organic phase, but also constructs an organic-inorganic hybrid cross-linking network in the silica sol matrix.

[0044] When glass fiber yarn is impregnated in a composite sol, the sol system undergoes sol-gel transformation and chemical cross-linking solidification on its surface and in its pores, causing PDA-BN to be uniformly distributed and firmly embedded in the fiber surface. Ultimately, under the triple action of the silicon-oxygen network, PDA-BN particles, and organic cross-linking agent, a multi-scale synergistic reinforcement structure is formed: BN imparts excellent thermal conductivity and mechanical reinforcement to the material, the PDA coating ensures interfacial bonding and dispersion stability, and the organic-inorganic hybrid network provides overall structural stability and durability, ultimately producing composite glass fiber yarn.

[0045] Further, in step C1, the ratio of hexagonal boron nitride sheet, Tris buffer, and dopamine hydrochloride is 100g:1500mL:1.5-3.0g, the pH of the Tris buffer is 8.5, and the post-processing includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake 3-5 times with anhydrous ethanol and deionized water, transfer the filter cake to a drying oven at 80℃, and vacuum dry it to constant weight to obtain PDA-BN powder;

[0046] Further, in step C2, the ratio of 3-glycidoxypropyltrimethoxysilane, tetraethoxysilane, deionized water and anhydrous ethanol, PDA-BN powder, 1,3-bis(1-isocyano-2-propyl)benzene and glass fiber yarn is 3-5g:6-8g:40-50mL:40mL:2-4g:1.5-3.0g:100g, wherein the diameter of the glass fiber yarn is 0.09-0.12mm. The post-treatment includes: after impregnation, drying at 120-140℃ for 2-4min, then activating at 160℃ for 1min, and then transferring the fiber to a drying oven at 60℃ and vacuum drying to constant weight to obtain composite glass fiber yarn.

[0047] Furthermore, the preparation method of flame-retardant microcapsules includes the following steps:

[0048] D1. Add hexachlorocyclotriphosphazene, sodium p-aminobenzenesulfonate, bisphenol A and 1,4-dioxane to a reaction vessel, heat under reflux for 2-3 hours with stirring, and then perform post-treatment to obtain phosphazene oligomers.

[0049] D2. Methyl methacrylate, isopropenyl oxazoline, methacryloxypropyltrimethoxysilane and azobisisobutyronitrile were added to the reaction vessel and stirred. The temperature of the reaction vessel was raised to 70-80℃ and core liquid was added dropwise to the reaction vessel. The dropwise addition was continued for 40-50 minutes. After the addition was completed, the mixture was kept warm and stirred for 2-3 hours. The flame-retardant microcapsules were obtained by post-treatment.

[0050] The reaction principle for preparing flame-retardant microcapsules can be summarized into three stages: construction of phosphazene oligomers, polymerization of functionalized monomers, and in-situ encapsulation of the core-wall structure.

[0051] First, through the substitution reaction of hexachlorocyclotriphosphazene with sodium p-aminobenzenesulfonate and bisphenol A, some chlorine atoms are replaced by active groups to generate phosphazene oligomers with polar substituents such as sulfonate groups and hydroxyl groups. These oligomers retain the thermal stability and phosphorus-rich characteristics of the cyclophosphazene skeleton, while introducing polar functional groups into the molecular chain, providing active sites for subsequent dispersibility and interfacial reactions.

[0052] Next, under the action of free radical initiators, functional monomers such as methyl methacrylate, isopropenyl oxazoline, and methacryloyloxypropyltrimethoxysilane undergo copolymerization to gradually form an organosilicon hybrid polymer containing carboxyl groups, oxazoline rings, and siloxane structures. During the reaction, the polymer gradually coats the surface of the core liquid particles and crosslinks or condenses with the polar groups of phosphazene oligomers through the ring-opening reaction of the oxazoline ring, the hydrolysis and condensation reaction of silane, thereby forming a chemically bonded composite interface layer at the core-wall interface.

[0053] Meanwhile, the core fluid is composed of ammonium polyphosphate and phosphazene oligomers, containing multiple phosphorus- and nitrogen-rich flame-retardant components. These substances can release phosphoric acid, phosphonic acid, and amino compounds at high temperatures, which dilute combustible gases and catalyze the formation of a char layer. Through the encapsulation of the microcapsule wall material, the core material is uniformly and stably dispersed in the polymer matrix, avoiding agglomeration and migration, and enabling gradual release during combustion, ultimately producing flame-retardant microcapsules.

[0054] Further, in step D1, the ratio of hexachlorocyclotriphosphazene, sodium p-aminobenzenesulfonate, bisphenol A and 1,4-dioxane is 1g:2-3g:2-3g:50mL. The post-processing includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator at a temperature of 100℃, and distill under reduced pressure until no liquid is collected to obtain phosphazene oligomers.

[0055] Further, in step D2, the ratio of methyl methacrylate, isopropenyl oxazoline, methacryloxypropyltrimethoxysilane, azobisisobutyronitrile, and core liquid is 0.9-1.1g:0.2-0.3g:0.05-0.08g:0.01g:40-50mL. The core liquid is prepared by mixing ammonium polyphosphate, phosphazene oligomer, polyvinyl alcohol, anhydrous ethanol, and deionized water in a ratio of 2.5g:0.3-0.5g:0.01-0.03g:20-30mL:20mL. The post-treatment includes: after the reaction is completed, the temperature of the reaction vessel is lowered to room temperature, the reaction solution is filtered to collect the filter cake, the filter cake is washed 3-5 times with anhydrous ethanol and deionized water, and then the filter cake is transferred to a drying oven at 80℃ and vacuum dried to constant weight to obtain flame-retardant microcapsules.

[0056] The present invention also relates to a super-fast charging liquid-cooled cable, which is prepared by the above-described method for preparing a super-fast charging liquid-cooled cable.

[0057] The present invention has the following beneficial effects:

[0058] 1. The liquid-cooled cable sheath layer of this invention incorporates aluminum hydroxide, which decomposes upon heating, absorbs heat, and releases water of crystallization, lowering the local temperature and diluting flammable gases, thus providing initial flame suppression and cooling. Simultaneously, flame-retardant microcapsules composed of phosphazene oligomers and ammonium polyphosphate continuously release phosphorus / nitrogen-containing species during thermal decomposition, promoting the formation of a dense, expanded carbon layer on the matrix surface, effectively blocking heat and oxygen. The microcapsule shell and matrix achieve a stable bond through interfacial interactions such as polarity and hydrogen bonding, reducing the risk of flame retardant migration and aggregation, and ensuring long-term stability of the flame-retardant function. Furthermore, the composite glass fiber yarn maintains its skeletal strength within the operating temperature range, and the combined heat-resistant properties of the silicon-oxygen network and PDA-BN filler provide structural support for the cable. This multi-scale synergistic mechanism enables the cable to possess rapid flame suppression capability in the initial stage of a flame and maintain good structural integrity and conductor protection under continuous heating conditions, thereby improving the flame-retardant rating and morphological stability at high temperatures.

[0059] 2. The composite glass fiber yarn of this invention is modified with PDA-BN powder and combined with silane sol-gel reaction to construct an organic-inorganic hybrid interface layer on the fiber surface, which significantly improves the interfacial bonding force between the fiber and the matrix, achieving a balance between high modulus and good toughness. In the shielding layer, annealed copper wire and composite glass fiber yarn are interwoven to form an interpenetrating skeleton: the copper wire provides a continuous metal bearing and conductive path, while the glass fiber inhibits deformation and disperses stress. At the same time, the Ag-MX conductive and thermally conductive colloid applied at the nodes forms a three-dimensional cross-linked resin network after curing and embeds conductive / thermal conductive fillers, firmly anchoring the copper wire-glass fiber intersection and reducing slippage and loosening at the nodes. In addition, the compatibilizers such as SEBS-g-MAH in the sheath layer improve the interfacial compatibility and energy dissipation capacity of the matrix-microcapsule / filler. Thus, under the synergistic effect of skeleton reinforcement, node stabilization and matrix toughening, the cable can more effectively disperse and transmit stress under stress conditions, exhibiting higher tensile strength.

[0060] 3. This invention utilizes PDA-modified boron nitride sheets uniformly loaded onto the surface of composite fiberglass yarn and incorporated into the shielding layer system. Surface functionalization significantly improves interfacial compatibility with the organic phase / silicon-oxygen network, inhibits agglomeration, and establishes a continuous, highly efficient in-plane thermally conductive network within the shielding layer, thereby reducing interfacial thermal resistance and improving thermal diffusion efficiency. Ag-MX conductive and thermally conductive colloid forms local electro-thermal bridges at the braiding nodes, promoting rapid heat conduction and diffusion between the copper wire, composite fiberglass, and the surrounding matrix. Simultaneously, in synergy with liquid cooling channels, it can further reduce operating temperature rise and improve thermal stability under high-power conditions. In terms of electromagnetic shielding, the copper wire braiding layer constitutes a continuous metal mesh, providing a dual mechanism of reflection and absorption. The composite fiberglass yarn enhances the structural stability of the braiding layer, reducing mesh changes caused by bending / stretching. After curing, the Ag-MX colloid at the nodes fills the intersections and gaps, significantly reducing potential electromagnetic leakage channels and lowering contact resistance, thereby achieving a more complete and stable shielding performance. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0062] Figure 1 This is a three-dimensional structural diagram of the liquid-cooled cable prepared according to the present invention;

[0063] In the diagram: 1. Cable core; 2. Shielding layer; 3. Heat exchange layer; 4. Sheath layer. Detailed Implementation

[0064] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0065] In this application, the maleic anhydride-grafted SEBS-g-MAH used was purchased from Shanghai Jiadeer Chemical Technology Co., Ltd., product number JD180508112249; the Ti3C2T used... xThe following materials were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.: Product No. T698838; Vinyl-terminated polydimethylsiloxane was purchased from Anhui Mingyi Silicon Industry Co., Ltd.: Product No. MY-273; Polymethylhydrosiloxane was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.: Product No. P750098; Hexagonal boron nitride sheets were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.: Product No. B874955; Ammonium polyphosphate was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.: Product No. A875116; Ethylene-acetic acid... The olefin copolymer was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., item number P815473; the Karstedt platinum catalyst used was purchased from Shanghai Haohong Biomedical Technology Co., Ltd., with a molecular weight of 949.36; the copper wire used was purchased from Tianjin Guangfu Technology Development Co., Ltd., item number gffxc1405; the zinc stearate used was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., item number Z820683; and the butene / ethylene / styrene copolymer used was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., item number PA91776.

[0066] Example 1

[0067] This embodiment provides a method for preparing a conductive and thermally conductive colloid for manufacturing super-fast charging liquid-cooled cables, including the following steps:

[0068] Step I: Preparation of Ag-MX composite powder

[0069] Weigh out: 10.0g Ti3C2T x Mixed with 1000.0 mL of deionized water, Ti3C2T was obtained. x Dispersion;

[0070] Weigh out 12.0 g of aminopropyltriethoxysilane, 5.0 g of silver nitrate, 6.0 g of polyvinylpyrrolidone, and 600.0 mL of deionized water and add them to a reaction vessel. Stir and add 150.0 mL of 1 mol / L ammonia solution dropwise over 15 minutes. After the addition is complete, add 11.0 g of glucose and 1000.0 mL of Ti3C2T. x The dispersion was stirred at room temperature for 30 minutes. After the reaction was completed, the temperature of the reactor was lowered to room temperature. The reaction solution was filtered to collect the filter cake. The filter cake was washed three times with anhydrous ethanol and deionized water. The filter cake was then transferred to a drying oven at 80°C and vacuum dried to constant weight to obtain Ag-MX composite powder.

[0071] Step II: Preparation of conductive and thermally conductive colloid

[0072] Weigh out 10.0g of Ag-MX composite powder, 3.0g of dipropylene glycol methyl ether, 80.0g of bisphenol A diglycidyl ether, 20.0g of m-xylenediamine, and 20.0g of vinyl-terminated polydimethylsiloxane and add them to a reaction vessel and stir. Add polymethylhydrosiloxane with a silanol group molar amount 1.2 times the vinyl group molar amount in the reaction system and 0.1g of Karstedt platinum catalyst. Raise the reaction vessel temperature to 80℃ and hold for 20 min, then raise the temperature to 120℃ and hold for 40 min. After the reaction is complete, allow the reaction vessel temperature to drop to room temperature, and then degas under vacuum for 10 min at a pressure of -0.08 MPa. Finally, use dipropylene glycol methyl ether to fine-tune the viscosity of the system to achieve a final viscosity of 25℃ for 10 seconds. -1 After the apparent viscosity was 20 Pa·s at the shear rate, the colloid was passed through a 100-mesh sieve to obtain a conductive and thermally conductive colloid.

[0073] Example 2

[0074] This embodiment provides a method for preparing a conductive and thermally conductive colloid for manufacturing super-fast charging liquid-cooled cables, including the following steps:

[0075] Step I: Preparation of Ag-MX composite powder

[0076] Weigh out: 20.0g Ti3C2T x Mixed with 1000.0 mL of deionized water, Ti3C2T was obtained. x Dispersion;

[0077] Weigh out 12.0 g of aminopropyltriethoxysilane, 7.0 g of silver nitrate, 6.0 g of polyvinylpyrrolidone, and 600.0 mL of deionized water and add them to a reaction vessel. Stir and add 150.0 mL of 1 mol / L ammonia solution dropwise over 20 minutes. After the addition is complete, add 2.2 g of glucose and 1000.0 mL of Ti3C2T. x The dispersion was stirred at room temperature for 40 minutes. After the reaction was completed, the temperature of the reactor was lowered to room temperature. The reaction solution was filtered to collect the filter cake. The filter cake was washed 5 times with anhydrous ethanol and deionized water. The filter cake was then transferred to a drying oven at 80°C and vacuum dried to constant weight to obtain Ag-MX composite powder.

[0078] Step II: Preparation of conductive and thermally conductive colloid

[0079] Weigh out 20.0g of Ag-MX composite powder, 3.0g of dipropylene glycol methyl ether, 100.0g of bisphenol A diglycidyl ether, 30.0g of m-xylenediamine, and 30.0g of vinyl-terminated polydimethylsiloxane and add them to the reactor and stir. Add polymethylhydrosiloxane with a silanol molar amount 1.3 times the molar amount of vinyl groups in the reaction system and 0.1g of Karstedt platinum catalyst. Raise the reactor temperature to 90℃ and hold for 30 min, then raise the temperature to 140℃ and hold for 60 min. After the reaction, allow the reactor temperature to drop to room temperature, and then degas under vacuum at -0.08 MPa for 20 min. Finally, use dipropylene glycol methyl ether to fine-tune the viscosity of the system to achieve a final viscosity of 25℃ for 10 seconds. -1 After the apparent viscosity at the shear rate is 30 Pa·s, the colloid is passed through a 100-mesh sieve to obtain a conductive and thermally conductive colloid.

[0080] Example 3

[0081] This embodiment provides a method for preparing a conductive and thermally conductive colloid for manufacturing super-fast charging liquid-cooled cables, including the following steps:

[0082] Step I: Preparation of Ag-MX composite powder

[0083] Weigh out: 16.0g Ti3C2T x Mixed with 1000.0 mL of deionized water, Ti3C2T was obtained. x Dispersion;

[0084] Weigh out 12.0 g of aminopropyltriethoxysilane, 6.0 g of silver nitrate, 6.0 g of polyvinylpyrrolidone, and 600.0 mL of deionized water and add them to a reaction vessel. Stir and add 150.0 mL of 1 mol / L ammonia solution dropwise over 18 minutes. After the addition is complete, add 16.0 g of glucose and 1000.0 mL of Ti3C2T. x The dispersion was stirred at room temperature for 36 minutes. After the reaction was completed, the temperature of the reactor was lowered to room temperature. The reaction solution was filtered to collect the filter cake. The filter cake was washed four times with anhydrous ethanol and deionized water. The filter cake was then transferred to a drying oven at 80°C and vacuum dried to constant weight to obtain Ag-MX composite powder.

[0085] Step II: Preparation of conductive and thermally conductive colloid

[0086] Weigh out 16.0g of Ag-MX composite powder, 3.0g of dipropylene glycol methyl ether, 96.0g of bisphenol A diglycidyl ether, 24.0g of m-xylenediamine, and 24.0g of vinyl-terminated polydimethylsiloxane and add them to the reactor and stir. Add polymethylhydrosiloxane with a silanol group molar amount 1.3 times the vinyl group molar amount in the reaction system and 0.1g of Karstedt platinum catalyst. Raise the reactor temperature to 88℃ and hold for 25 min, then raise the temperature to 130℃ and hold for 50 min. After the reaction, allow the reactor temperature to drop to room temperature, and then degas under vacuum for 16 min at a pressure of -0.08 MPa. Finally, use dipropylene glycol methyl ether to fine-tune the viscosity of the system to achieve the desired effect at 25℃ for 10 seconds. -1 After the apparent viscosity at the shear rate is 25 Pa·s, the colloid is passed through a 100-mesh sieve to obtain a conductive and thermally conductive colloid.

[0087] Example 4

[0088] This embodiment provides a method for preparing composite glass fiber yarn for super-fast charging liquid-cooled cables, including the following steps:

[0089] Step ①: Preparation of PDA-BN powder

[0090] Weigh out 100.0g of hexagonal boron nitride tablets, 1500.0mL of Tris buffer solution at pH=8.5, and 1.5g of dopamine hydrochloride and add them to the reaction vessel. Stir gently at room temperature for 2 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake four times with anhydrous ethanol and deionized water, and then transfer the filter cake to a drying oven at 80℃ and vacuum dry it to constant weight to obtain PDA-BN powder.

[0091] Step 2: Preparation of composite glass fiber yarn

[0092] Weigh out 30.0g of 3-glycidoxypropyltrimethoxysilane, 60.0g of tetraethoxysilane, 400.0mL of deionized water and 400.0mL of anhydrous ethanol and add them to a reaction vessel. Add glacial acetic acid to adjust the pH of the reaction system to 4. Age at 40℃ for 1h to obtain silane sol. Then add 20.0g of PDA-BN powder and 15.0g of 1,3-bis(1-isocyano-2-propyl)benzene to the silane sol to obtain a composite sol. Then impregnate 100.0g of glass fiber yarn with a diameter of 0.09mm into the composite sol for 11min. After impregnation, remove it and dry it at 120℃ for 2min, then activate it at 160℃ for 1min. Then transfer the fiber to a drying oven at 60℃ and vacuum dry it to constant weight to obtain composite glass fiber yarn.

[0093] Example 5

[0094] This embodiment provides a method for preparing composite glass fiber yarn for super-fast charging liquid-cooled cables, including the following steps:

[0095] Step ①: Preparation of PDA-BN powder

[0096] Weigh out 100.0g of hexagonal boron nitride tablets, 1500.0mL of Tris buffer solution at pH=8.5, and 3.0g of dopamine hydrochloride and add them to the reaction vessel. Stir gently at room temperature for 4 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake 5 times with anhydrous ethanol and deionized water, and then transfer the filter cake to a drying oven at 80℃ and vacuum dry it to constant weight to obtain PDA-BN powder.

[0097] Step 2: Preparation of composite glass fiber yarn

[0098] Weigh out 50.0g of 3-glycidoxypropyltrimethoxysilane, 80.0g of tetraethoxysilane, 500.0mL of deionized water, and 400.0mL of anhydrous ethanol and add them to a reaction vessel. Add glacial acetic acid to adjust the pH of the reaction system to 5. Aging at 40℃ for 2h yields a silane sol. Then add 40.0g of PDA-BN powder and 30.0g of 1,3-bis(1-isocyano-2-propyl)benzene to the silane sol to obtain a composite sol. Then impregnate 100.0g of glass fiber yarn with a diameter of 0.12mm into the composite sol for 2min. After impregnation, remove the yarn and dry it at 140℃ for 4min, then activate it at 160℃ for 1min. Finally, transfer the fiber to a drying oven at 60℃ and vacuum dry it to constant weight to obtain the composite glass fiber yarn.

[0099] Example 6

[0100] This embodiment provides a method for preparing composite glass fiber yarn for super-fast charging liquid-cooled cables, including the following steps:

[0101] Step ①: Preparation of PDA-BN powder

[0102] Weigh out 100.0g of hexagonal boron nitride tablets, 1500.0mL of Tris buffer solution at pH=8.5, and 2.4g of dopamine hydrochloride and add them to the reaction vessel. Stir gently at room temperature for 3 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake 4 times with anhydrous ethanol and deionized water, and then transfer the filter cake to a drying oven at 80℃ and vacuum dry it to constant weight to obtain PDA-BN powder.

[0103] Step 2: Preparation of composite glass fiber yarn

[0104] Weigh out 40.0g of 3-glycidoxypropyltrimethoxysilane, 72.0g of tetraethoxysilane, 450.0mL of deionized water, and 400.0mL of anhydrous ethanol and add them to a reaction vessel. Add glacial acetic acid to adjust the pH of the reaction system to 4. Age at 40℃ for 2h to obtain a silane sol. Then add 30.0g of PDA-BN powder and 24.0g of 1,3-bis(1-isocyano-2-propyl)benzene to the silane sol to obtain a composite sol. Then immerse 100.0mm diameter glass fiber yarn in the composite sol for 2min. After immersion, remove the yarn and dry it at 135℃ for 3min. Then activate it at 160℃ for 1min. Transfer the fiber to a drying oven at 60℃ and vacuum dry it to constant weight to obtain the composite glass fiber yarn.

[0105] Example 7

[0106] This embodiment provides a method for preparing flame-retardant microcapsules for super-fast charging liquid-cooled cables, including the following steps:

[0107] Step (1): Preparation of phosphazene oligomers

[0108] Weigh out 10.0 g of hexachlorocyclotriphosphazene, 20.0 g of sodium p-aminobenzenesulfonate, 20.0 g of bisphenol A and 500.0 mL of 1,4-dioxane and add them to a reaction vessel. Heat under reflux for 2 h with stirring. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator at 100 °C, and distill under reduced pressure until no liquid is collected to obtain phosphazene oligomers.

[0109] Step 2: Preparation of flame-retardant microcapsules

[0110] Weigh out 25.0g ammonium polyphosphate, 3.0g phosphazene oligomer, 0.1g polyvinyl alcohol, 200.0mL anhydrous ethanol and 200.0mL deionized water and mix them to obtain the core solution;

[0111] Weigh out 9.0g of methyl methacrylate, 2.0g of isopropenyl oxazoline, 0.5g of methacryloyloxypropyltrimethoxysilane, and 0.1g of azobisisobutyronitrile and add them to a reaction vessel. Stir the mixture and raise the temperature of the reaction vessel to 70℃. Add 400.0mL of core solution dropwise to the reaction vessel for 40min. After the addition is complete, continue stirring at the same temperature for 2h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake three times with anhydrous ethanol and deionized water. Transfer the filter cake to a drying oven at 80℃ and vacuum dry it to constant weight to obtain flame-retardant microcapsules.

[0112] Example 8

[0113] This embodiment provides a method for preparing flame-retardant microcapsules for super-fast charging liquid-cooled cables, including the following steps:

[0114] Step (1): Preparation of phosphazene oligomers

[0115] Weigh out 10.0 g of hexachlorocyclotriphosphazene, 30.0 g of sodium p-aminobenzenesulfonate, 30.0 g of bisphenol A and 500.0 mL of 1,4-dioxane and add them to the reaction vessel. Heat under reflux for 3 h with stirring. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator at 100 °C, and distill under reduced pressure until no liquid is collected to obtain phosphazene oligomers.

[0116] Step 2: Preparation of flame-retardant microcapsules

[0117] Weigh out 25.0g ammonium polyphosphate, 5.0g phosphazene oligomer, 0.3g polyvinyl alcohol, 300.0mL anhydrous ethanol and 200.0mL deionized water and mix them to obtain the core solution;

[0118] Weigh out 11.0 g of methyl methacrylate, 3.0 g of isopropenyl oxazoline, 0.8 g of methacryloyloxypropyltrimethoxysilane, and 0.1 g of azobisisobutyronitrile and add them to a reaction vessel. Stir the mixture and raise the temperature of the reaction vessel to 80 °C. Add 500.0 mL of core solution dropwise to the reaction vessel for 50 min. After the addition is complete, continue stirring at the same temperature for 3 h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake 5 times with anhydrous ethanol and deionized water. Transfer the filter cake to a drying oven at 80 °C and vacuum dry it to constant weight to obtain flame-retardant microcapsules.

[0119] Example 9

[0120] This embodiment provides a method for preparing flame-retardant microcapsules for super-fast charging liquid-cooled cables, including the following steps:

[0121] Step (1): Preparation of phosphazene oligomers

[0122] Weigh out 10.0 g of hexachlorocyclotriphosphazene, 25.0 g of sodium p-aminobenzenesulfonate, 25.0 g of bisphenol A and 500.0 mL of 1,4-dioxane and add them to a reaction vessel. Heat under reflux for 3 h with stirring. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator at 100 °C, and distill under reduced pressure until no liquid is collected to obtain phosphazene oligomers.

[0123] Step 2: Preparation of flame-retardant microcapsules

[0124] Weigh out 25.0g ammonium polyphosphate, 4.0g phosphazene oligomer, 0.2g polyvinyl alcohol, 25.0mL anhydrous ethanol and 200.0mL deionized water and mix them to obtain the core solution;

[0125] Weigh out 10.0g of methyl methacrylate, 2.5g of isopropenyl oxazoline, 0.6g of methacryloyloxypropyltrimethoxysilane, and 0.1g of azobisisobutyronitrile and add them to a reaction vessel. Stir the mixture and raise the temperature of the reaction vessel to 75℃. Add 450.0mL of core solution dropwise to the reaction vessel for 45min. After the addition is complete, continue stirring at the same temperature for 2h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake four times with anhydrous ethanol and deionized water. Transfer the filter cake to a drying oven at 80℃ and vacuum dry it to constant weight to obtain flame-retardant microcapsules.

[0126] Example 10

[0127] This embodiment provides a method for preparing a super-fast charging liquid-cooled cable, including the following steps:

[0128] Step 1: Preparing the cable core

[0129] Cable core 1 is obtained by stranding seven copper wires with a surface coating of 0.7 mm thick polyvinyl chloride insulation and a diameter of 0.5 mm.

[0130] Step 2: Prepare the shielding layer

[0131] Annealed copper wire with a diameter of 0.12 mm and composite glass fiber yarn prepared in Example 4 were fed into a braiding machine for interlacing and weaving. The number of strands of the annealed copper wire was 16 and the number of strands of the composite glass fiber yarn was 8. The weaving coverage was controlled at 85%, the tension was maintained at 0.2 N, and the linear speed was controlled at 10 m / min to obtain the precursor of modified fiber cloth.

[0132] The conductive and thermally conductive colloid prepared in Example 1 was dotted onto the nodes of the modified fiber cloth precursor with a dotting thickness of 100 μm. During the dotting process, only the nodes were treated and the entire surface was not covered. After the dotting was completed, the material was pre-cured at 120°C for 5 min and then shaped and cured at 150°C for 10 min to obtain the modified fiber cloth.

[0133] The modified fiber cloth is wrapped around the cable core to obtain shielding layer 2.

[0134] Step 3: Prepare the heat exchange layer

[0135] Weigh out 70.0 mL of deionized water, 30.0 mL of ethylene glycol, and 0.1 g of methylbenzotriazole and mix them to obtain the heat exchange fluid;

[0136] Eighteen copper heat exchange tubes with an outer diameter of 8 mm and a thickness of 0.5 mm were spirally arranged on the surface of the shielding layer. Heat exchange fluid was introduced and kept at a flow rate of 1.2 m / s to obtain heat exchange layer 3.

[0137] Step 4: Prepare liquid-cooled cables

[0138] By weight, 40 parts of butene / ethylene / styrene copolymer, 15 parts of flame-retardant microcapsules prepared in Example 7, 25 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride-grafted SEBS-g-MAH, 35 parts of aluminum hydroxide, 2 parts of zinc stearate, and 2 parts of N,N'-diphenyl-p-phenylenediamine were weighed and added to a twin-screw extruder. In the twin-screw extruder, the temperatures of the eight temperature zones from the feed port to the discharge port were 150°C, 155°C, 155°C, 160°C, 170°C, 175°C, 180°C, and 185°C, respectively. The main motor speed of the twin-screw extruder was 80 rpm, and the pressure was 100 bar. The melt extrusion coated the shielding layer surface, solidified, and demolded to obtain a sheath layer 4 with a thickness of 1.5 mm, which is the liquid-cooled cable.

[0139] Example 11

[0140] This embodiment provides a method for preparing a super-fast charging liquid-cooled cable, including the following steps:

[0141] Step 1: Preparing the cable core

[0142] Cable core 1 is obtained by stranding seven copper wires with a surface coating of 0.7 mm thick polyvinyl chloride insulation and a diameter of 0.5 mm.

[0143] Step 2: Prepare the shielding layer

[0144] Annealed copper wire with a diameter of 0.18 mm and composite glass fiber yarn prepared in Example 5 were fed into a braiding machine for interlacing and weaving. The number of strands of the annealed copper wire was 24, and the number of strands of the composite glass fiber yarn was 12. The weaving coverage was controlled at 95%, the tension was maintained at 0.4 N, and the linear speed was controlled at 20 m / min to obtain the modified fiber cloth precursor.

[0145] The conductive and thermally conductive colloid prepared in Example 2 was dotted onto the nodes of the modified fiber cloth precursor with a dotting thickness of 120 μm. During the dotting process, only the nodes were treated and the entire surface was not covered. After the dotting was completed, the material was pre-cured at 140°C for 8 min and then shaped and cured at 160°C for 15 min to obtain the modified fiber cloth.

[0146] The modified fiber cloth is wrapped around the cable core to obtain shielding layer 2.

[0147] Step 3: Prepare the heat exchange layer

[0148] Weigh out 70.0 mL of deionized water, 30.0 mL of ethylene glycol, and 0.1 g of methylbenzotriazole and mix them to obtain the heat exchange fluid;

[0149] Eighteen copper heat exchange tubes with an outer diameter of 8 mm and a thickness of 0.5 mm were spirally arranged on the surface of the shielding layer. Heat exchange fluid was introduced and kept at a flow rate of 1.2 m / s to obtain heat exchange layer 3.

[0150] Step 4: Prepare liquid-cooled cables

[0151] By weight, 45 parts of butene / ethylene / styrene copolymer, 25 parts of flame-retardant microcapsules prepared in Example 8, 35 parts of ethylene-vinyl acetate copolymer, 10 parts of maleic anhydride-grafted SEBS-g-MAH, 50 parts of aluminum hydroxide, 2 parts of zinc stearate, and 3 parts of N,N'-diphenyl-p-phenylenediamine were weighed and added to a twin-screw extruder. In the twin-screw extruder, the temperatures of the eight temperature zones from the feed port to the discharge port were 150°C, 155°C, 155°C, 160°C, 170°C, 175°C, 180°C, and 185°C, respectively. The main motor speed of the twin-screw extruder was 120 rpm, and the pressure was 150 bar. The melt extrusion coated the shielding layer surface, solidified, and demolded to obtain a sheath layer 4 with a thickness of 1.5 mm, which is the liquid-cooled cable.

[0152] Example 12

[0153] This embodiment provides a method for preparing a super-fast charging liquid-cooled cable, including the following steps:

[0154] Step 1: Preparing the cable core

[0155] Cable core 1 is obtained by stranding seven copper wires with a surface coating of 0.7 mm thick polyvinyl chloride insulation and a diameter of 0.5 mm.

[0156] Step 2: Prepare the shielding layer

[0157] Annealed copper wire with a diameter of 0.15 mm and composite glass fiber yarn prepared in Example 6 were fed into a braiding machine for interlacing and weaving. The number of strands of the annealed copper wire was 20 and the number of strands of the composite glass fiber yarn was 10. The weaving coverage was controlled at 90%, the tension was maintained at 0.3 N, and the linear speed was controlled at 15 m / min to obtain the precursor of modified fiber cloth.

[0158] The conductive and thermally conductive colloid prepared in Example 3 was dotted onto the nodes of the modified fiber cloth precursor with a dotting thickness of 100 μm. During the dotting process, only the nodes were treated and the entire surface was not covered. After the dotting was completed, the material was pre-cured at 130°C for 6 min and then shaped and cured at 160°C for 12 min to obtain the modified fiber cloth.

[0159] The modified fiber cloth is wrapped around the cable core to obtain shielding layer 2.

[0160] Step 3: Prepare the heat exchange layer

[0161] Weigh out 70.0 mL of deionized water, 30.0 mL of ethylene glycol, and 0.1 g of methylbenzotriazole and mix them to obtain the heat exchange fluid;

[0162] Eighteen copper heat exchange tubes with an outer diameter of 8 mm and a thickness of 0.5 mm were spirally arranged on the surface of the shielding layer. Heat exchange fluid was introduced and kept at a flow rate of 1.2 m / s to obtain heat exchange layer 3.

[0163] Step 4: Prepare liquid-cooled cables

[0164] By weight, 42 parts of butene / ethylene / styrene copolymer, 20 parts of flame-retardant microcapsules prepared in Example 9, 30 parts of ethylene-vinyl acetate copolymer, 9 parts of maleic anhydride-grafted SEBS-g-MAH, 45 parts of aluminum hydroxide, 2 parts of zinc stearate, and 3 parts of N,N'-diphenyl-p-phenylenediamine were weighed and added to a twin-screw extruder. In the twin-screw extruder, the temperatures of the eight temperature zones from the feed port to the discharge port were 150°C, 155°C, 155°C, 160°C, 170°C, 175°C, 180°C, and 185°C, respectively. The main motor speed of the twin-screw extruder was 100 rpm, and the pressure was 120 bar. The melt extrusion coated the shielding layer surface, solidified, and demolded to obtain a sheath layer 4 with a thickness of 1.5 mm, which is the liquid-cooled cable.

[0165] Comparative Example 1

[0166] The difference between this comparative example and Example 12 is that step ① is omitted in the preparation process of the composite glass fiber yarn used in step 3.

[0167] Comparative Example 2

[0168] The difference between this comparative example and Example 12 is that the conductive and thermally conductive colloid is omitted in step three.

[0169] Comparative Example 3

[0170] The difference between this comparative example and Example 12 is that the flame-retardant microcapsules are omitted in step four.

[0171] Performance testing:

[0172] The flame retardancy rating of the liquid-cooled cables prepared in Examples 10-12 and Comparative Examples 1-3 was tested in accordance with the standard GB / T 19666-2019 "General Rules for Flame Retardant and Fire Resistant Wires, Cables or Optical Cables".

[0173] The fire resistance ratings of the liquid-cooled cables prepared in Examples 10-12 and Comparative Examples 1-3 were tested in accordance with standard XF 306.2-2007 "Flame-retardant and fire-resistant cables - Classification and requirements of plastic insulated flame-retardant and fire-resistant cables - Part 2: Fire-resistant cables".

[0174] The tensile strength of the liquid-cooled cables prepared in Examples 10-12 and Comparative Examples 1-3 was tested in accordance with standard XF 306.1-2007 "Flame-retardant and fire-resistant cables - Classification and requirements of plastic insulated flame-retardant and fire-resistant cables - Part 1: Flame-retardant cables".

[0175] The shielding effectiveness of the liquid-cooled cables prepared in Examples 10-12 and Comparative Examples 1-3 was tested in accordance with the standard GB / T 32511-2016 "General Technical Requirements for Electromagnetic Shielding Plastics". The specific data are shown in Table 1.

[0176] The thermal conductivity of the modified fiber cloths prepared in Examples 9-12 and Comparative Examples 1-3 was tested according to the standard GB / T 10297-2015 "Determination of Thermal Conductivity of Non-metallic Solid Materials - Hot Wire Method". The specific data are shown in Table 1.

[0177] Table 1 - Performance Test Data for Each Sample

[0178]

[0179] Data Analysis:

[0180] Comparative analysis of the data in Table 1 reveals that the liquid-cooled cable prepared by this invention has a flame retardant rating of IA, a fire resistance rating of IA, a tensile strength of 30.2 MPa, and an electromagnetic interference resistance rating of SE-1. Simultaneously, the modified fiber cloth prepared with this invention has a thermal conductivity of 10.2015 W·(m·K). -1 All data points are better than the comparative data, indicating that:

[0181] Comparative Example 1 omitted the surface treatment of the glass fiber, resulting in a lack of effective interfacial bonding between the fiber and the matrix. Without this interfacial adhesion, the glass fiber acts more like an "isolated skeleton" within the system, failing to form a cohesive whole with the outer layer. When the material is heated, the difference in thermal expansion between the fiber surface and the matrix leads to micro-cracks and peeling at the interface, significantly weakening the supporting effect. Furthermore, thermal stress cannot be uniformly transferred, amplifying localized melting and collapse, making it difficult for the flame-retardant layer to maintain its integrity. The ultimate result is a simultaneous decrease in heat resistance and structural stability. The functions of maintaining shape and delaying flame penetration, which should be undertaken by the glass fiber skeleton, are greatly diminished, and the overall integrity and reliability of the material under high-temperature impact are significantly weakened.

[0182] Comparative Example 2 eliminated the node bridging / crosslinking effect of the conductive and thermally conductive adhesive, resulting in fibers being maintained only by physical contact, lacking effective anchoring points, and losing bridging. Under stress, the fiberglass braided structure is prone to slippage, increasing internal porosity. After heating, the fiber network loosens, making it difficult to sustain support. Due to the lack of stable nodes, load and thermal stress transmission are interrupted, manifesting as localized stress concentration and uneven deformation. The outer layer is more prone to bulging and tearing under thermal shock and mechanical disturbance. Simultaneously, heat and gas can more easily penetrate through the pores, reducing the integrity and insulation performance of the flame-retardant layer. Overall, the lack of node bridging renders the originally stable mesh skeleton unrestrained, leading to a significant reduction in thermo-mechanical dual coupling performance.

[0183] Comparative Example 3 eliminated the phosphorus / nitrogen synergistic flame-retardant components, disrupting the char layer formation mechanism. Without the dual role of gas-phase free radical capture and condensed-phase catalytic char formation, the material could only form a loose, cracked char layer at high temperatures, failing to provide a stable thermal barrier. During pyrolysis, matrix decomposition products were more likely to escape and participate in combustion, leading to more intense reactions in the flame zone and an increased heat release rate. Simultaneously, the lack of a dense char layer exposed the glass fiber skeleton at high temperatures, further accelerating structural instability. Ultimately, this resulted in a shortened flame-retardant durability, making the material more prone to collapse or breakdown under flame or electrothermal action, significantly reducing its withstand time and safety margin.

[0184] In conclusion, this solution achieves a multi-level synergistic effect through surface modification of glass fiber, stabilization of structural nodes, and synergistic design of flame-retardant components. After surface treatment, the glass fiber can be tightly bonded to the matrix to form a tough skeleton structure, providing reliable morphology retention for the overall material. Node bridging further stabilizes the fiber network, ensuring its integrity under thermal stress and mechanical impact, preventing failure due to loosening. The flame-retardant system rapidly generates a dense char layer in high-temperature environments, forming an effective barrier with the fiber skeleton to block the continuous intrusion of heat and flame. The interaction of these three factors not only improves the long-term stability of heat resistance and flame retardancy but also takes into account structural strength and safety margin, exhibiting comprehensive performance far superior to single modification approaches. This multi-factor coupling enables the liquid-cooled cable to demonstrate more reliable and durable performance in complex application environments.

[0185] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a super-fast charging liquid-cooled cable, characterized in that, Includes the following steps: S1. Several copper wires with polyvinyl chloride insulation layer on their surface are twisted together to obtain a cable core (1). S2. A shielding layer (2) is obtained by wrapping the cable core (1) with modified fiber cloth. S3. Several heat exchange tubes are spirally arranged on the surface of the shielding layer (2) to obtain the heat exchange layer (3). S4. Butene / ethylene / styrene copolymer, flame-retardant microcapsules and auxiliary materials are melt-extruded and coated on the surface of the heat exchange layer (3). After curing, a sheath layer (4) is obtained, thus obtaining a liquid-cooled cable. The method for preparing the modified fiber cloth includes the following steps: A1. Annealed copper wire and composite glass fiber yarn are fed into a weaving machine for interlacing weaving, controlling the weaving coverage to be 85-95%, the tension to be maintained at 0.2-0.4N, and the linear speed to be controlled at 10-20m / min, to obtain the modified fiber cloth precursor. A2. Apply the conductive and thermally conductive colloid to the nodes of the modified fiber cloth precursor with a thickness of 100-120μm. During the application process, only the nodes are treated without covering the entire surface. The modified fiber cloth is then obtained through post-processing.

2. The method for preparing a super-fast charging liquid-cooled cable according to claim 1, characterized in that, In the process of preparing modified fibers, in step A1, the number of strands of annealed copper wire is 16-24, and the number of strands of composite glass fiber yarn is 8-12, wherein the diameter of copper wire is 0.12-0.18mm; in step A2, the post-treatment includes: after the dot coating is completed, the material is pre-cured at 120-140℃ for 5-8min, and then shaped and cured at 150-160℃ for 10-15min to obtain modified fiber cloth.

3. The method for preparing a super-fast charging liquid-cooled cable according to claim 2, characterized in that, The method for preparing the conductive and thermally conductive colloid includes the following steps: B1. Add aminopropyltriethoxysilane, silver nitrate, polyvinylpyrrolidone, and deionized water to a reaction vessel, stir, and add ammonia dropwise. After the addition is completed within 15-20 minutes, add glucose and Ti3C2T. x The dispersion was stirred at room temperature for 30-40 minutes, and then post-processed to obtain Ag-MX composite powder. B2. Add Ag-MX composite powder, dipropylene glycol methyl ether, bisphenol A diglycidyl ether, m-xylenediamine and vinyl-terminated polydimethylsiloxane to a reactor and stir. After adding the calculated amount of polymethylhydrosiloxane and Karstedt platinum catalyst, raise the reactor temperature to 80-90℃ and keep it at that temperature for 20-30 min. Then raise the temperature to 120-140℃ and keep it at that temperature for 40-60 min. The post-treatment yields a conductive and thermally conductive colloid.

4. The method for preparing a super-fast charging liquid-cooled cable according to claim 1, characterized in that, The method for preparing the composite glass fiber yarn includes the following steps: C1. Add hexagonal boron nitride sheets, Tris buffer and dopamine hydrochloride to the reaction vessel, stir gently at room temperature for 2-4 hours, and then process to obtain PDA-BN powder. C2. Add 3-glycidoxypropyltrimethoxysilane, tetraethoxysilane, deionized water and anhydrous ethanol to a reaction vessel, add glacial acetic acid to adjust the pH of the reaction system to 4-5, and age at 40℃ for 1-2 hours to obtain silane sol. Then add PDA-BN powder and 1,3-bis(1-isocyano-2-propyl)benzene to the silane sol to obtain composite sol. Then impregnate glass fiber yarn into the composite sol for 1-2 minutes, and post-process to obtain composite glass fiber yarn.

5. The method for preparing a super-fast charging liquid-cooled cable according to claim 4, characterized in that, In step C1, the ratio of hexagonal boron nitride tablets, Tris buffer, and dopamine hydrochloride is 100g:1500mL:1.5-3.0g; in step C2, the ratio of 3-glycidoxypropyltrimethoxysilane, tetraethoxysilane, deionized water and anhydrous ethanol, PDA-BN powder, 1,3-bis(1-isocyano-2-propyl)benzene, and glass fiber yarn is 3-5g:6-8g:40-50mL:40mL:2-4g:1.5-3.0g:100g, wherein the diameter of the glass fiber yarn is 0.09-0.12mm.

6. The method for preparing a super-fast charging liquid-cooled cable according to claim 1, characterized in that, The method for preparing the flame-retardant microcapsules includes the following steps: D1. Add hexachlorocyclotriphosphazene, sodium p-aminobenzenesulfonate, bisphenol A and 1,4-dioxane to a reaction vessel, heat under reflux for 2-3 hours with stirring, and then perform post-treatment to obtain phosphazene oligomers. D2. Methyl methacrylate, isopropenyl oxazoline, methacryloxypropyltrimethoxysilane and azobisisobutyronitrile were added to the reaction vessel and stirred. The temperature of the reaction vessel was raised to 70-80℃ and core liquid was added dropwise to the reaction vessel. The dropwise addition was continued for 40-50 minutes. After the addition was completed, the mixture was kept warm and stirred for 2-3 hours. The flame-retardant microcapsules were obtained by post-treatment.

7. The method for preparing a super-fast charging liquid-cooled cable according to claim 6, characterized in that, In step D1, the ratio of hexachlorocyclotriphosphazene, sodium p-aminobenzenesulfonate, bisphenol A, and 1,4-dioxane is 1g:2-3g:2-3g:50mL; in step D2, the ratio of methyl methacrylate, isopropenyloxazoline, methacryloxypropyltrimethoxysilane, azobisisobutyronitrile, and core liquid is 0.9-1.1g:0.2-0.3g:0.05-0.08g:0.01g:40-50mL, wherein the core liquid is obtained by mixing ammonium polyphosphate, phosphazene oligomer, polyvinyl alcohol, anhydrous ethanol, and deionized water in a ratio of 2.5g:0.3-0.5g:0.01-0.03g:20-30mL:20mL.

8. A super-fast charging liquid-cooled cable, characterized in that, The super-fast charging liquid-cooled cable is prepared using the method described in any one of claims 1-7.

Images