A lightweight self-healing cable and its preparation method

Abstract

This invention relates to a lightweight self-healing cable and its manufacturing method. The cable comprises a composite tubular conductor, a self-healing insulation layer, a shielding layer, and an outer sheath containing degradable components. The composite tubular conductor is formed by online concentric encapsulation and radial compaction of an aluminum or aluminum alloy tubular fluid carrier, continuous carbon fiber reinforcing bundles, and a heat-resistant resin adhesive layer. The self-healing insulation layer contains a microcapsule repair agent that can release the core material to fill microcracks. The manufacturing method includes carbon fiber bundle pre-shaping, online encapsulation of the tubular fluid carrier, radial compaction, low-temperature low-shear preparation of the insulating composite masterbatch, extrusion cross-linking, and forming of the shielding layer and outer sheath. This cable is advantageous for reducing metal usage and improving mechanical stability and insulation repair capabilities.

Description

Technical Field

[0001] This invention relates to the field of cable and electrical materials technology, specifically to a lightweight self-healing cable with a composite tubular conductor and a self-healing insulation layer, and its preparation method. Background Technology

[0002] Applications such as new energy vehicles, photovoltaic power plants, energy storage systems, and smart grids place comprehensive demands on the conductivity, mechanical strength, insulation reliability, weather resistance, and material utilization efficiency of cables. Traditional cables mostly use solid copper or solid aluminum conductors. Solid copper conductors have higher conductivity, but their density and material cost are higher; solid aluminum conductors can reduce weight, but there is still room for improvement in tensile strength, fatigue stability, and resistance to localized damage.

[0003] Existing insulation layers may develop microscopic damage such as microcracks, water trees, or electrical trees under the influence of laying, bending, thermal cycling, moisture, and long-term electric fields. If the damage occurs within the insulation layer that directly bears the withstand voltage function, traditional insulation materials are usually unable to repair it in time, and the micro-damage may continue to expand, leading to a decrease in insulation strength. Some cables have incorporated microcapsule-type self-healing structures in their sheath or outer coating, but these structures mainly target sheath cracks and have limited effectiveness in the early repair of microcracks within the insulation layer.

[0004] Composite reinforced conductors also incorporate combinations of carbon fiber and metallic materials. For example, some designs use hollow steel wires filled with carbon fiber composite materials, with multiple composite reinforcing steel wires twisted together to form a reinforcing core, and then externally stranded with heat-resistant aluminum alloy wires. While this structure improves tensile strength, the current-carrying, reinforcing core, and cable insulation systems still primarily rely on layered or stranded structures, making it difficult to directly address issues such as coaxial positioning, interface voids, and consistency in continuous forming between the tubular current-carrying conductor and the continuous carbon fiber reinforcing bundle.

[0005] Furthermore, commonly used sheath materials contain a high proportion of non-degradable components, and waste disposal and material recycling still require improvement. Simply adding recycled or biodegradable materials may affect the sheath's weather resistance, abrasion resistance, and impact resistance. Therefore, a lightweight, self-healing cable that achieves synergistic design in conductor structure, insulation repair, shielding, and outer sheath materials is needed. Summary of the Invention

[0006] Technical problems to be solved The present invention aims to at least solve the problems of existing cables, such as large weight, insufficient mechanical stability of conductors, difficulty in timely repair of microcracks in insulation layers, insufficient consistency of the interface between composite reinforcing core and current-carrying conductor, and difficulty in balancing the recyclability and protective performance of outer sheath materials.

[0007] Technical solution To address the aforementioned technical problems, this invention provides a lightweight self-healing cable. The cable comprises, from the inside out, a composite tubular conductor, a self-healing insulation layer, a shielding layer, and an outer sheath containing degradable components, arranged coaxially. The composite tubular conductor includes an aluminum or aluminum alloy tubular current carrier, continuous carbon fiber reinforcing bundles, and a heat-resistant resin bonding layer. After being impregnated and pre-shaped with heat-resistant resin, the continuous carbon fiber reinforcing bundles are concentrically wrapped online with the aluminum or aluminum alloy tubular current carrier and radially compacted, forming a continuous interfacial bonding structure after curing.

[0008] The self-healing insulation layer is directly extruded onto the outer periphery of the composite tubular conductor and provides electrical insulation. The self-healing insulation layer is formed from an insulating base material and microcapsule repair agents dispersed within it. The microcapsule repair agents can use urea-formaldehyde resin as the wall material and epoxy resin, latent curing polyetheramine components, an epoxy-polyetheramine composite repair system with isolated encapsulations, or a combination thereof, as the core material. When microcracks develop in the self-healing insulation layer, the localized stress at the crack tip causes adjacent microcapsules to rupture, releasing the core material which then impregnates, polymerizes, or cures at the crack, thereby filling the microcrack.

[0009] The shielding layer can be a composite tape wrapped with tin-plated copper and recycled modified polyethylene terephthalate (PET); the outer protective layer containing degradable components can be formed by blending recycled modified polyolefin, biodegradable polyester, modified starch, antioxidants, light stabilizers and weather-resistant fillers.

[0010] The present invention also provides a method for preparing the above-mentioned cable, including the steps of pre-forming continuous carbon fiber bundles, online concentric wrapping of tubular fluid-carrying material, radial compaction and gradient cooling, low-temperature and low-shear preparation of self-healing insulation composite masterbatch, extrusion, gradient cooling, cross-linking, shielding layer wrapping and outer sheath extrusion.

[0011] Beneficial effects Compared with the prior art, the present invention has at least the following beneficial effects: First, the composite tubular conductor forms an interfacial bonding structure with the continuous carbon fiber reinforcing bundle through an aluminum or aluminum alloy tubular fluid carrier, which can reduce the amount of conductor metal while meeting the current carrying requirements, and improve the axial tensile strength through carbon fiber; Second, the continuous carbon fiber reinforcing bundle is first impregnated and pre-shaped, and then concentrically wrapped and radially compacted with the tubular fluid carrier in the line, which helps to reduce eccentricity, voids and interfacial gaps; Third, the microcapsule repair agent is arranged in the insulation layer that directly undertakes the electrical insulation function, which can release and repair the core material for early microcracks in the insulation layer; Fourth, low-temperature low-shear mixing, masterbatch maturation, segmented temperature-controlled extrusion and gradient cooling help to reduce the risk of microcapsule breakage during processing and improve the molding consistency of the self-healing insulation layer; Fifth, the shielding layer and the outer protective layer containing degradable components help to reduce the amount of metal and non-degradable materials used. Attached Figure Description

[0012] Figure 1This is a schematic cross-sectional view of the overall structure of the lightweight self-healing cable of the present invention.

[0013] Figure 2 This is a schematic cross-sectional view of the composite tubular conductor of the present invention.

[0014] Figure 3 This is a schematic diagram of the structure of the microcapsule repair agent of the present invention.

[0015] Figure 4 This is a schematic diagram of the microcrack repair process in the self-healing insulation layer of the present invention.

[0016] Figure 5 This is a flowchart of the integrated continuous forming process of the composite tubular conductor of the present invention.

[0017] Figure 6 This is a flowchart of the self-healing insulation layer and subsequent cable fabrication process of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 10, cable; 11, composite tubular conductor; 111, aluminum or aluminum alloy tubular current carrier; 112, continuous carbon fiber reinforcing bundle; 113, heat-resistant resin adhesive layer; 20, self-healing insulation layer; 21, insulation base material; 22, microcapsule repair agent; 221, wall material; 222, core material; 30, shielding layer; 40, outer sheath containing degradable components; 60, repair agent; 70, microcrack. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the following embodiments are used to illustrate the technical concept of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can reasonably adjust the material grade, layer thickness, process parameters, and testing conditions without changing the concept of online concentric coating of composite tubular conductors and low-damage molding of self-healing insulation layers. Unless otherwise stated, percentages in this application are mass percentages, and parts by mass are parts by mass calculated according to the corresponding basis.

[0020] Overall cable structure like Figure 1 As shown, the cable 10 comprises, from the inside out, a composite tubular conductor 11, a self-healing insulation layer 20, a shielding layer 30, and an outer sheath 40 containing degradable components. The composite tubular conductor 11 serves as both a current-carrying channel and an axial reinforcement member; the self-healing insulation layer 20 is directly extruded around the outer periphery of the composite tubular conductor 11 and provides electrical insulation; the shielding layer 30 is located outside the self-healing insulation layer 20 and is used for shielding and grounding continuity; the outer sheath 40 containing degradable components is located on the outermost side and is used for abrasion resistance, weather resistance, and environmental protection.

[0021] Composite tubular conductors and their preparation like Figure 2As shown, the composite tubular conductor 11 includes an aluminum or aluminum alloy tubular current carrier 111, a continuous carbon fiber reinforcing bundle 112, and a heat-resistant resin adhesive layer 113. The aluminum or aluminum alloy tubular current carrier 111 forms the main current-carrying path; the continuous carbon fiber reinforcing bundle 112 is disposed along the cable axis within the cavity of the aluminum or aluminum alloy tubular current carrier 111; the heat-resistant resin adhesive layer 113 is located between the two, so that the continuous carbon fiber reinforcing bundle 112 and the tubular current carrier 111 form a whole after curing.

[0022] In one embodiment, the wall thickness of the aluminum or aluminum alloy tubular fluid carrier 111 is 0.8-1.5 mm; the material can be 1060 or 1070 electrical pure aluminum or 8030 series aluminum alloy that meets the conductivity requirements. When using electrical pure aluminum, it can be annealed at 340-380℃ for 1-2 hours, followed by air cooling to eliminate work hardening; when using 8030 series aluminum alloy, it can be annealed at 380-420℃ for 4-6 hours, followed by air cooling. The conductivity is expressed as %IACS converted from resistivity at 20℃; where 100%IACS corresponds to the standard conductivity of annealed copper at 20℃.

[0023] The continuous carbon fiber reinforced bundle 112 can be selected from polyacrylonitrile (PAN) based continuous carbon fiber bundles or T700 grade continuous carbon fiber bundles, with a single filament diameter of 7-12 μm and a carbon content of not less than 95%. The heat-resistant resin can be modified epoxy resin, polyimide resin or their composite system, with a temperature resistance rating of not less than 200℃.

[0024] The composite tubular conductor 11 can be prepared according to the following steps. First, the carbon fiber bundle is desizing with hot air and then enters the impregnation tank, where it is impregnated with resin at 45-55℃. After impregnation, the carbon fiber bundle is subjected to a sizing and scraping device to remove excess resin, and then enters a pre-curing channel at 120-140℃ to form a semi-cured continuous carbon fiber core. This step is used to improve the shape retention of the bundle and reduce the risk of fraying, misalignment, and insufficient resin during subsequent online coating.

[0025] Then, the semi-cured continuous carbon fiber core is continuously passed through the central channel of the concentric coating die under constant tension; aluminum or aluminum alloy material is continuously extruded or hot-extruded to form a tubular fluid carrier, which is then coated onto the outer periphery of the semi-cured continuous carbon fiber core online. The raw material can be homogenized aluminum or aluminum alloy rods with a diameter of φ8-φ12 mm. During production, the preheating temperature of the aluminum or aluminum alloy rods can be controlled at 550-570℃, the temperature of the coating forming zone or extrusion chamber can be controlled at 590-620℃, and the die temperature can be controlled at 600±20℃, so that the aluminum or aluminum alloy material is in a thermoplastic state suitable for continuous flow and coating forming. The extrusion pressure can be controlled at 80-120 MPa, the extrusion roller speed can be set to 15-25 r / min, and the overall coating traction speed is matched with the carbon fiber core conveying speed and can be controlled at 5-15 m / min.

[0026] An annular sizing and compaction device can be installed at the die outlet to perform overall radial compaction and correction of the tubular fluid carrier and semi-cured continuous carbon fiber core with a radial compaction pressure of 5-10 MPa. During the production process, the surface temperature of the carbon fiber core can be controlled to not exceed 150℃ through the die insulation structure and continuous core material conveying, thereby reducing the impact of high temperature on the pre-impregnated resin structure of the carbon fiber core surface.

[0027] Finally, the coated composite conductor undergoes gradient cooling. Gradient cooling may include initial slow cooling with 50-70°C warm water, followed by ambient warm water cooling, and then air cooling for dehydration, shaping and straightening, eddy current testing, and constant tension winding. This cooling method is used to reduce the risks of internal stress, aluminum tube cracking, resin thermal damage, and core material misalignment caused by rapid cooling.

[0028] The concentricity error of the composite tubular conductor can be measured by sampling along its continuous length. Specifically, cross-sections are taken at different axial positions of the sample, polished, and then cross-sectional images are obtained. The offset between the center of the continuous carbon fiber reinforcing bundle and the center of the outer circle of the tubular fluid carrier is measured, and the maximum offset is taken as the concentricity error. The interface adhesion rate can be calculated by the ratio of the continuous adhesion arc length measured by the microscopic cross-sectional image to the theoretical interface perimeter, or by the ratio of the equivalent contact area to the theoretical interface area.

[0029] Self-healing insulating layer and its preparation like Figure 3 As shown, the microcapsule repair agent 22 includes a wall material 221 and a core material 222. The wall material 221 can be selected from urea-formaldehyde resin; the core material 222 can be selected from epoxy resin, a latent curing component of polyetheramine, an epoxy-polyetheramine composite repair system or a combination thereof that is isolated and encapsulated from each other. To reduce the risk of premature reaction, a single-capsule latent curing system can be used, or a dual-capsule system that separately encapsulates the epoxy component and the polyetheramine component can be used.

[0030] The insulating base material 21 of the self-healing insulating layer 20 can be cross-linked ethylene-vinyl acetate copolymer (EVA), cross-linked polyolefin, bio-based polyolefin, or a combination thereof. The particle size of the microcapsule repair agent 22 can be 20-50 μm, and the addition amount can be 8%-15% of the mass of the insulating base material. When the self-healing insulating layer 20 is subjected to bending, thermal cycling, or local electric field action, microcracks 70 are generated. The stress at the crack tip causes the adjacent microcapsules to rupture, and the core material 222, as the repair agent 60, is released and impregnates along the microcracks 70, subsequently polymerizing or curing to form a filling area, such as... Figure 4 As shown.

[0031] The preparation of the self-healing insulation layer 20 may include microcapsule pretreatment, low-temperature low-shear mixing, masterbatch maturation, extrusion, gradient cooling, and crosslinking. Microcapsule pretreatment includes sieving to remove impurities and drying at 45-55℃ under low-temperature hot air conditions for 20-40 min to reduce the impact of adsorbed water and broken particles on insulation performance. After plasticizing and premixing the insulation base material at 110-125℃, the microcapsule repair agent is added in batches and mixed under low shear for 8-12 min. After mixing, the mixture is extruded and granulated, and then matured at room temperature for 2-4 h to obtain the self-healing insulation composite masterbatch.

[0032] Extrusion employs segmented temperature control. The feeding section temperature can be 110-125℃, the plasticizing section temperature can be 125-135℃, and the die head temperature can be 135-145℃. After extrusion, the material is first slowly cooled and shaped in 50-60℃ warm water, and then cooled in ambient warm water. After cooling and resting, a crosslinking process matching the base material system can be used; when using electron beam irradiation crosslinking, the irradiation dose can be 25-40 kGy, and the production line speed can be 5-15 m / min. The above process reduces the risk of microcapsule breakage during processing by controlling the microcapsule pretreatment temperature, mixing shear strength, extrusion residence time, and cooling gradient.

[0033] The insulation strength recovery rate R is calculated as R = E1 / E0 × 100%, where R is the insulation strength recovery rate, E0 is the breakdown strength of the self-healing insulation layer in the undamaged state, in kV / mm; and E1 is the breakdown strength of the self-healing insulation layer after micro-cracks are generated and static repair is completed, in kV / mm.

[0034] Shielding layer and outer protective layer containing degradable components The shielding layer 30 can be constructed using a composite tape wrapped with tin-plated copper and recycled modified polyethylene terephthalate (PET), with an overlap of 20%-25% and a copper layer thickness of 0.02-0.04 mm. This structure reduces the amount of metal used while maintaining shielding and grounding continuity, and improves the stability of the tape by utilizing the recycled modified polyethylene terephthalate base layer.

[0035] The outer sheath 40 containing degradable components can be made of a blend of recycled modified polyolefin and biodegradable polyester. Based on 100 parts by weight of the total weight of the recycled modified polyolefin, biodegradable polyester, and modified starch, the outer sheath may include 50-65 parts by weight of recycled modified polypropylene (PP) and / or recycled modified polyethylene (PE), 25-40 parts by weight of polybutylene adipate terephthalate (PBAT), and 5-10 parts by weight of modified starch, with one or more additives selected from antioxidants, light stabilizers, and weather-resistant fillers. The recycled modified polyolefin in this outer sheath provides a mechanical protection base, PBAT and modified starch increase the proportion of degradable components, and weather-resistant additives improve stability under outdoor use conditions.

[0036] Example 1: Lightweight self-healing cable for new energy vehicles The cable in this embodiment consists of, from the inside out, a composite tubular conductor, a self-healing insulation layer, a shielding layer, and an outer sheath containing degradable components. The composite tubular conductor is made of aluminum or aluminum alloy tubular fluid carrier with a wall thickness of 1.0 mm. Continuous polyacrylonitrile (PAN) based carbon fiber bundles are placed inside the tube, and a heat-resistant resin bonding layer is formed using modified epoxy resin. The composite tubular conductor is manufactured using the aforementioned online concentric coating, radial compaction, and gradient cooling process.

[0037] Samples were taken from the same continuous preparation batch, and the cross-sections were polished and subjected to microscopic image analysis. The concentricity error of the composite tubular conductor in the continuous length direction was measured to be no greater than 0.1 mm, and the interface bonding rate between the continuous carbon fiber reinforcing bundle and the tubular fluid carrier was no less than 95%. The overall tensile strength of the composite tubular conductor was measured to be no less than 380 MPa according to the conductor tensile test.

[0038] The self-healing insulation layer uses cross-linked ethylene-vinyl acetate copolymer (EVA) as the base material, with microcapsule repair agent added at 12% of the insulation base material mass. The microcapsule core material is an epoxy-polyetheramine repair system, and the insulation layer thickness is 0.5 mm. The shielding layer is wrapped with a composite tape of tin-plated copper and recycled modified polyethylene terephthalate (PET), with an overlap rate of 22%. The outer sheath is formulated with recycled modified polypropylene (PP), polybutylene adipate terephthalate (PBAT), and modified starch in a mass ratio of 60:32:8, and weather-resistant additives are added.

[0039] Microcracks were prepared on self-healing insulation layer samples at 25℃ and 50%±5% relative humidity. Microcracks with a width of 5-20 μm were prepared on the surface of the insulation layer using a micro-scratcher and a diamond conical scratch needle. After the microcracks were prepared, the crack width was measured using a 500-1000x optical microscope with image analysis software, and the average value was taken from multiple measurement points along the crack length.

[0040] Insulation breakdown strength testing was conducted according to GB / T 1408.1-2016 "Electrical Strength Test Methods for Insulating Materials - Part 1: Power Frequency Tests". The test used 25 mm diameter cylindrical brass electrodes and performed power frequency withstand voltage tests in air at a voltage ramp rate of 1 kV / s. The ambient temperature was 25℃ and the relative humidity was 50%±5%. Ten valid parallel samples were set up for each group, and the arithmetic mean was taken after discarding samples with edge breakdown or abnormal breakdown.

[0041] The test results are as follows: the initial breakdown strength E0 of the self-healing insulation layer in the undamaged state is 35 kV / mm; after the formation of 5-20 μm microcracks and standing at 25℃ for 24 h, the breakdown strength E1 after repair is 32.2 kV / mm; calculated according to E1 / E0×100%, the insulation strength recovery rate is 92%.

[0042] Example 2: Lightweight self-healing cable for photovoltaic applications This embodiment is basically the same as Embodiment 1, except that: the tubular fluid-carrying wall thickness of the composite tubular conductor is 1.2 mm, and the continuous carbon fiber reinforcing bundles are densely arranged to adapt to long-distance outdoor laying conditions; the self-healing insulation layer uses bio-based polyolefin base material, the amount of microcapsule repair agent added is 15% of the mass of the insulation base material, and the insulation layer thickness is 0.6 mm; the outer sheath is made of recycled modified polyethylene (PE), polybutylene adipate terephthalate (PBAT) and modified starch in a mass ratio of 55:38:7, and light stabilizers and weather-resistant fillers are added.

[0043] The outer sheath of this embodiment can be evaluated by fluorescent ultraviolet lamp exposure test according to GB / T 16422.3; the self-healing insulation layer can be evaluated for insulation strength recovery rate according to the microcrack preparation, static setting and breakdown strength test method described in Example 1.

[0044] Example 3: Lightweight self-healing cable for energy storage systems This embodiment is basically the same as Embodiment 1, except that: according to the current carrying requirements of the energy storage system, multiple composite tubular conductors can be stranded together to form a conductor unit; a halogen-free intumescent flame retardant can be added to the self-healing insulation layer, which can be a compound system of ammonium polyphosphate, pentaerythritol and melamine, and the amount added can be 18%-22% of the total mass of the self-healing insulation layer; the thickness of the outer sheath containing degradation components can be increased to 1.2 mm to improve wear resistance and impact resistance.

[0045] Comparison and performance testing To illustrate the role of online concentric wrapping and self-healing insulation layer on composite tubular conductors, the following comparative example is set up.

[0046] Table 1. Process Comparison of Composite Tubular Conductors

[0047] Table 2 Comparison of Self-Healing Insulation Layers

[0048] As shown in Table 1, the combined effects of continuous carbon fiber core pre-curing, tubular fluid-carrying online concentric coating, radial compaction, and gradient cooling are beneficial in maintaining concentricity and interfacial adhesion along the continuous length. As shown in Table 2, dispersing the microcapsule repair agent within the insulating layer that directly performs electrical insulation functions can improve the breakdown strength recovery rate after microcrack formation.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Equivalent substitutions or conventional adjustments made by those skilled in the art to material grades, layer thicknesses, process parameters, and application scenarios within the scope of the present invention should all fall within the protection scope of the present invention.

Claims

1. A lightweight self-healing cable, characterized in that, The cable comprises, from the inside out, a composite tubular conductor, a self-healing insulation layer, a shielding layer, and an outer sheath containing degradable components, arranged coaxially. The composite tubular conductor includes an aluminum or aluminum alloy tubular fluid carrier, a continuous carbon fiber reinforcing bundle located along the cable axis within the tubular fluid carrier cavity, and a heat-resistant resin bonding layer located between the tubular fluid carrier and the continuous carbon fiber reinforcing bundle. The continuous carbon fiber reinforcing bundle is pre-shaped by impregnation with heat-resistant resin, then concentrically wrapped online with the tubular fluid carrier and radially compacted, allowing the continuous carbon fiber reinforcing bundle to be bonded by the cured heat-resistant resin. The layer forms a continuous interface with the tubular fluid carrier; the self-healing insulation layer is directly extruded onto the outer periphery of the composite tubular conductor and undertakes the function of electrical insulation. The self-healing insulation layer is formed by an insulating base material and a microcapsule repair agent dispersed in the insulating base material. When a microcrack occurs in the self-healing insulation layer, the microcapsule repair agent ruptures and releases the core material to fill the microcrack; the shielding layer is a composite tape wrapping layer formed by metal and recycled modified polyester; the outer protective layer containing degradable components is formed by blending recycled modified polyolefin, biodegradable polyester and modified starch.

2. The lightweight self-healing cable according to claim 1, characterized in that, The aluminum or aluminum alloy tubular fluid carrier has a wall thickness of 0.8-1.5 mm and an electrical conductivity of not less than 60% IACS at 20℃; the continuous carbon fiber reinforcing bundle is a polyacrylonitrile-based continuous carbon fiber bundle or a T700 grade continuous carbon fiber bundle, with a single filament diameter of 7-12 μm and a carbon content of not less than 95%; the heat-resistant resin is a modified epoxy resin, polyimide resin, or a composite resin of the two with a temperature resistance rating of not less than 200℃.

3. The lightweight self-healing cable according to claim 1, characterized in that, The concentricity error of the composite tubular conductor in the continuous length direction is not greater than 0.1 mm, the interface bonding rate between the continuous carbon fiber reinforcing bundle and the tubular fluid carrier is not less than 95%, and the overall tensile strength of the composite tubular conductor is not less than 380 MPa.

4. The lightweight self-healing cable according to claim 1, characterized in that, The thickness of the self-healing insulation layer is 0.3-0.8 mm, and the insulation matrix is ​​a cross-linked ethylene-vinyl acetate copolymer matrix, a polyolefin matrix, a bio-based polyolefin matrix, or a combination thereof.

5. The lightweight self-healing cable according to claim 1, characterized in that, The microcapsule repair agent uses urea-formaldehyde resin as the wall material and epoxy resin, polyetheramine latent curing components, and an epoxy-polyetheramine composite repair system or a combination thereof that is isolated and encapsulated from each other as the core material. The particle size is 20-50 μm, and the amount added is 8%-15% of the mass of the insulating base material.

6. The lightweight self-healing cable according to claim 1, characterized in that, After the self-healing insulation layer forms microcracks with a width of 5-20 μm, the insulation strength recovery rate after standing at 25°C for 24 h is not less than 90%; the insulation strength recovery rate is E1 / E0×100%, where E0 is the breakdown strength of the self-healing insulation layer in the undamaged state, and E1 is the breakdown strength of the self-healing insulation layer after the microcracks are formed and it is left to stand.

7. The lightweight self-healing cable according to claim 1, characterized in that, The shielding layer is a composite tape wrapped with tin-plated copper and recycled modified polyethylene terephthalate, with a wrapping overlap rate of 20%-25% and a copper layer thickness of 0.02-0.04 mm.

8. The lightweight self-healing cable according to claim 1, characterized in that, Based on a total mass of 100 parts by mass of the recycled modified polyolefin, biodegradable polyester, and modified starch, the outer protective layer containing degradable components comprises 50-65 parts by mass of recycled modified polypropylene and / or recycled modified polyethylene, 25-40 parts by mass of polybutylene adipate terephthalate, and 5-10 parts by mass of modified starch, and includes one or more additives selected from antioxidants, light stabilizers, and weather-resistant fillers.

9. A method for preparing a lightweight self-healing cable according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. The continuous carbon fiber bundle is subjected to desizing, impregnation with heat-resistant resin, sizing, and pre-curing to form a semi-cured continuous carbon fiber core. S2. The semi-cured continuous carbon fiber core is continuously passed through the central channel of a concentric coating die under constant tension, and aluminum or aluminum alloy material is continuously extruded or hot-extruded to form a tubular fluid carrier, which is then online coated around the periphery of the semi-cured continuous carbon fiber core. S3. The composite conductor obtained in step S2 is subjected to annular sizing, compaction, and gradient cooling to solidify and bond the semi-cured continuous carbon fiber core with the tubular fluid carrier, resulting in a composite tubular conductor. S4. The insulating base material is mixed with the pretreated microcapsule repair agent at low temperature and low shear and granulated to obtain a self-healing insulating composite masterbatch. S5. The self-healing insulating composite masterbatch is extruded, gradient cooled, and cross-linked around the periphery of the composite tubular conductor to form a self-healing insulating layer. S6. A shielding layer is sequentially wrapped around the outside of the self-healing insulating layer, and an outer protective layer containing degradation components is extruded.

10. The preparation method according to claim 9, characterized in that, In step S1, the continuous carbon fiber bundles are desizing with hot air and then enter the impregnation tank, where they are impregnated with resin at 45-55℃. After sizing and scraping, they enter the pre-curing channel at 120-140℃. In step S3, the gradient cooling includes slow cooling with warm water at 50-70℃ followed by cooling with ambient water. In step S4, the microcapsule repair agent is dried under low-temperature hot air conditions at 45-55℃ for 20-40 minutes, and the insulating base material is plasticized and premixed at 110-125℃. Subsequently, the microcapsule repair agent is added in batches and mixed under low shear for 8-12 minutes. In step S5, the extrusion adopts segmented temperature control, with the feeding section temperature at 110-125℃, the plasticizing section temperature at 125-135℃, and the die temperature at 135-145℃. The thickness of the self-healing insulating layer is controlled by linking the traction speed with the extrusion flow rate.

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