New energy automobile cable

Abstract

The invention discloses a new energy automobile cable, which sequentially comprises a central conductor, an insulating layer, a braided shielding layer, an aluminum foil shielding layer and an outer sheath layer from inside to outside, and is characterized in that the insulating layer and the outer sheath layer are respectively and independently formed by extruding halogen-free flame-retardant heat-conducting polyolefin materials; the halogen-free flame-retardant heat-conducting polyolefin material is prepared from the following raw materials in parts by weight: 70 to 80 parts of high-density polyethylene, 20 to 30 parts of ethylene-vinyl acetate copolymer, 5 to 10 parts of heat-treated Mxene, 10 parts of diethyl aluminum hypophosphite, 0.2 to 1 part of silane coupling agent and 0.7 to 4 parts of phospholipid compound. The insulating layer and the outer sheath layer are prepared from a halogen-free flame-retardant heat-conducting polyolefin material, so that the heat dissipation effect is remarkably improved while the insulating property is ensured, the service life of the cable is prolonged, the cable is environment-friendly and flame-retardant, and the emission of toxic gas in a fire disaster can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and in particular relates to new energy vehicle cables. Background Art

[0002] At present, the new energy vehicle industry shoulders the dual missions of industrial transformation and upgrading and protecting the atmospheric environment. It has greatly promoted the industrial development of high-voltage cables and other related accessories for electric vehicles. Various cable manufacturers and certification agencies have invested a lot of energy in the research and development of cables for electric vehicles.

[0003] In order to increase the charging speed and efficiency, the charging current of the charging pile for new energy vehicles has reached 250A, which is bound to increase the heat generated by thermal conductivity. Under the impact of long-term high current, the insulation layer of the charging cable will accelerate aging, shorten the service life, and increase maintenance costs. Therefore, how to improve the rapid heat dissipation of the charging cable has become a research hotspot.

[0004] Forced cooling, phase change, and insulation modification technologies are widely researched for enhancing heat dissipation in cables. Forced cooling, however, requires adding coolant channels to the center or outside of the cable core, which creates production difficulties and is therefore less commonly used. Phase change, on the other hand, requires filling the cable insulation with phase change material. However, during repeated phase change cycles, the material's thermophysical properties degrade, reducing its energy storage capacity. Furthermore, the capsule-type filling method typically used affects the mechanical properties of the insulation. Therefore, adding thermally conductive fillers to cable insulation is one of the most effective methods for improving heat dissipation.

[0005] Currently, fillers used in cable insulation layers include silicon carbide, boron nitride, and various carbon allotropes. However, in order to achieve the thermal conductivity required by the thermal interface material, the volume ratio of the filler often needs to be as high as 60%. However, this will result in excessive density of the insulation layer material and poor mechanical properties. Therefore, providing a new energy vehicle cable with both good heat dissipation and mechanical properties is a technical problem that needs to be solved. Summary of the Invention

[0006] The purpose of the present invention is to provide a new energy vehicle cable to solve the problem in the prior art that new energy vehicle cables are difficult to have both good heat dissipation performance and mechanical properties.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A new energy vehicle cable, which includes a central conductor, an insulation layer, a braided shielding layer, an aluminum foil shielding layer and an outer sheath layer from the inside to the outside.

[0009] As a preferred technical solution of the present invention, the insulating layer and the outer sheath layer are independently extruded from a halogen-free, flame-retardant, and thermally conductive polyolefin material.

[0010] As a preferred technical solution of the present invention, the halogen-free flame-retardant thermally conductive polyolefin material comprises the following raw materials in parts by weight:

[0011] 70-80 parts of high-density polyethylene, 20-30 parts of ethylene-vinyl acetate copolymer, 5-10 parts of heat-treated Mxene, 10 parts of diethyl aluminum hypophosphite, 0.2-1 parts of silane coupling agent, and 0.7-4 parts of phospholipid compound.

[0012] As a preferred technical solution of the present invention, the halogen-free flame-retardant thermally conductive polyolefin material further includes 0.1-1 parts by weight of an antioxidant.

[0013] As a preferred technical solution of the present invention, the halogen-free flame-retardant thermally conductive polyolefin material further includes 1-3 parts by weight of a lubricant.

[0014] As a preferred technical solution of the present invention, the heat-treated Mxene is TiO2 / Ti3C2T x Composite materials.

[0015] As a preferred technical solution of the present invention, the silane coupling agent is at least one of epoxy silane, carboxyl silane and amino silane.

[0016] As a preferred technical solution of the present invention, the epoxysilane is at least one of 3-glycidoxypropyltrimethoxysilane, 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane and 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane.

[0017] As a preferred technical solution of the present invention, the carboxyl silane is 3-(triethoxysilyl)propyl succinic anhydride and / or 3-[3-carboxyallylamide]propyl triethoxysilane.

[0018] As a preferred technical solution of the present invention, the aminosilane is at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane and γ-aminopropylethoxydimethylsilane.

[0019] As a preferred technical solution of the present invention, the phospholipid compound is phosphatidylserine and / or L-phosphatidylethanolamine.

[0020] As a preferred technical solution of the present invention, the preparation method of heat-treated Mxene comprises the following steps:

[0021] After mixing hydrochloric acid solution and deionized water, sodium fluoride was added and stirred at 60 °C until sodium fluoride was completely dissolved. Then Ti3AlC2 powder was added and ultrasonicated for 30 minutes. The mixture was kept warm and magnetically stirred for 48 hours. The mixture was centrifuged, the precipitate was washed and vacuum dried to obtain Ti3C2T x Materials: Ti3C2T x The material is transferred to a muffle furnace and heat-treated at 300-700° C. for 2-4 h in an air atmosphere to obtain heat-treated Mxene.

[0022] Mxene is a two-dimensional material, which is a general term for transition metal carbides or carbonitrides. It has excellent thermal conductivity and electrical conductivity. x Type Mxene is widely used. Its two-dimensional structure forms a larger contact area between them, providing a wider path for the transmission of phonons, reducing the interface contact thermal resistance, and is conducive to the construction of the heat conduction network in the system, which can better improve the thermal conductivity of the material. However, Ti3C2T x Mxene also has excellent electrical conductivity. When its content is high, it will form a thermal conductive network and affect the insulation performance of the system. To solve this problem, the present invention adopts a controllable heat treatment process to treat Ti3C2T x Surface modification is carried out by heating Ti3C2T in an oxidizing atmosphere at 300-700℃. x Irregular TiO2 nanoparticles are generated on the surface of the material. On the one hand, nano-TiO2 acts as a wide bandgap semiconductor in Ti3C2T x An insulating barrier is constructed on the surface of the sheet to increase the volume resistivity of the composite material. On the other hand, nano-TiO2 has certain thermal conductivity, which helps the continuity of the thermal network, so that the composite material can still maintain good thermal conductivity and insulation at a low thermal conductive filler content.

[0023] As a preferred technical solution of the present invention, the usage ratio of hydrochloric acid solution, deionized water, sodium fluoride and Ti3AlC2 powder in the above-mentioned heat-treated Mxene preparation process is 20-30 mL: 20-30 mL: 2 g: 1.5-2 g, and the mass fraction of the hydrochloric acid solution is 36-38%.

[0024] As a preferred technical solution of the present invention, the antioxidant is at least one of 1010, 1076, 168, 626, 300 and DSTDP.

[0025] As a preferred technical solution of the present invention, the lubricant is at least one of calcium stearate, zinc stearate, paraffin wax and polyethylene wax.

[0026] As a preferred technical solution of the present invention, the halogen-free flame-retardant thermally conductive polyolefin material is made by the following steps:

[0027] The raw materials are weighed according to a weight ratio and placed in a mixer for uniform mixing. The raw materials are then transferred to a twin-screw extruder for extrusion and granulation to obtain a halogen-free flame-retardant thermally conductive polyolefin material.

[0028] As a preferred technical solution of the present invention, the mixer speed is 500-1500 rpm and the mixing time is 15-60 min.

[0029] As a preferred technical solution of the present invention, the extrusion temperature is 160-190°C.

[0030] As a preferred technical solution of the present invention, the central conductor is a twisted wire core.

[0031] As a preferred technical solution of the present invention, the material of the central conductor is one of a bare copper conductor, a tinned copper conductor and a nickel-plated copper conductor.

[0032] As a preferred technical solution of the present invention, the braided shielding layer is woven from tinned copper wires, and the braiding density is 90-95%.

[0033] As a preferred technical solution of the present invention, the aluminum foil shielding layer is a polyimide aluminum-plastic composite tape with a thickness of 0.03 mm.

[0034] Beneficial effects of the present invention:

[0035] (1) The present invention provides a new energy vehicle cable, which uses a twisted wire core as a central conductor, which is beneficial to enhancing the flexibility and bending fatigue resistance of the cable and adapting to complex installation environments; the insulation layer and the outer sheath layer are prepared using halogen-free flame-retardant thermal conductive polyolefin material, which ensures the insulation performance while significantly improving the heat dissipation effect, which is beneficial to extending the service life of the cable, and is environmentally friendly and flame-retardant, and can reduce toxic gas emissions during fires; through the double-layer shielding structure and optimized braiding density, the cable's anti-electromagnetic interference ability is improved, ensuring stable signal transmission; the multi-layer insulation design is adopted to improve the high voltage resistance and prevent corona discharge and local discharge.

[0036] (2) The halogen-free flame-retardant thermally conductive polyolefin material of the present invention is composed of raw materials such as high-density polyethylene, ethylene-vinyl acetate copolymer, heat-treated Mxene, diethyl aluminum hypophosphite, silane coupling agent, and phospholipid compound. During the raw material mixing and extrusion process, the silane coupling agent combines with the heat-treated Mxene to improve the dispersibility of the heat-treated Mxene in the matrix, which is beneficial to stress transfer and improves the mechanical properties of the composite material. The heat-treated Mxene forms a thermal conductive network in the matrix, ensuring the insulation performance while significantly providing the heat dissipation performance of the composite material. In addition, the phospholipid compound combines with the silane coupling agent through hydrogen bonds or chemical reactions to form an organic modification layer containing nitrogen, phosphorus, and silicon elements and alkyl long chains on the surface of the heat-treated Mxene. The alkyl long chains can be inserted into the polymer, reducing the polymer interaction force and improving the flexibility of the composite material. The nitrogen, phosphorus, and silicon elements are beneficial to improving the flame retardant properties of the composite material.

[0037] (3) The heat-treated Mxene in the present invention has good structural stability, which not only can play the catalytic role of transition metal oxides in the polymer combustion process, but also the lamellar structure will produce a barrier effect, thereby achieving a good flame retardant effect of the composite material. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0039] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, a~b (i.e., a and b), a~c, b~c, or a~b~c, where a, b, c can be single or multiple.

[0040] The terms used in the examples of this application are for the purpose of describing specific implementation rules only and are not intended to limit this application. The singular forms "a", "an", "the" and "the" used in the implementation rules of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0041] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0042] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass described in the examples of this application may be a mass unit known in the chemical industry, such as μg, mg, g, kg, etc.

[0043] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0044] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0045] In response to the problem that new energy vehicle cables in the existing technology are difficult to have both good heat dissipation performance and mechanical properties, the embodiments of the present application provide new energy vehicle cables, which include, from the inside to the outside, a center conductor, an insulation layer, a braided shielding layer, an aluminum foil shielding layer and an outer sheath layer.

[0046] The insulating layer and the outer sheath layer are independently formed by extruding a halogen-free flame-retardant heat-conductive polyolefin material.

[0047] The halogen-free flame-retardant thermally conductive polyolefin material comprises the following raw materials in parts by weight:

[0048] 70-80 parts of high-density polyethylene, 20-30 parts of ethylene-vinyl acetate copolymer, 5-10 parts of heat-treated Mxene, 10 parts of diethyl aluminum hypophosphite, 0.2-1 parts of silane coupling agent, and 0.7-4 parts of phospholipid compound.

[0049] In some specific embodiments, the halogen-free flame-retardant thermally conductive polyolefin material further includes 0.1-1 parts by weight of an antioxidant.

[0050] In some specific embodiments, the halogen-free flame-retardant thermally conductive polyolefin material further includes 1-3 parts by weight of a lubricant.

[0051] In some specific embodiments, the heat-treated Mxene is TiO2 / Ti3C2T x Composite materials.

[0052] In some specific embodiments, the silane coupling agent is at least one of epoxy silane, carboxyl silane and amino silane.

[0053] In some specific embodiments, the epoxysilane is at least one of 3-glycidoxypropyltrimethoxysilane, 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane.

[0054] In some specific embodiments, the carboxyl silane is 3-(triethoxysilyl)propyl succinic anhydride and / or 3-[3-carboxyallylamido]propyl triethoxysilane.

[0055] In some specific embodiments, the aminosilane is at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane and γ-aminopropylethoxydimethylsilane.

[0056] In some specific embodiments, the phospholipid compound is phosphatidylserine and / or L-phosphatidylethanolamine.

[0057] In some specific embodiments, the method for preparing the heat-treated MXene comprises the following steps:

[0058] Mix hydrochloric acid solution and deionized water, add sodium fluoride, stir at 60℃ until sodium fluoride is completely dissolved, then add Ti3AlC2 powder, ultrasonicate for 30min, keep warm and stir with magnetic stirring for 48h, centrifuge, wash the precipitate and vacuum dry to obtain Ti3C2T x Materials: Ti3C2T x The material is transferred to a muffle furnace and heat-treated at 300-700° C. for 2-4 h in an air atmosphere to obtain heat-treated Mxene.

[0059] Mxene is a two-dimensional material, which is a general term for transition metal carbides or carbonitrides. It has excellent thermal conductivity and electrical conductivity. x Type Mxene is widely used. Its two-dimensional structure forms a larger contact area between them, providing a wider path for the transmission of phonons, reducing the interface contact thermal resistance, and is conducive to the construction of the heat conduction network in the system, which can better improve the thermal conductivity of the material. However, Ti3C2T x Mxene also has excellent electrical conductivity. When its content is high, it will form a thermal conductive network and affect the insulation performance of the system. To solve this problem, the present invention adopts a controllable heat treatment process to treat Ti3C2T xSurface modification is carried out by heating Ti3C2T in an oxidizing atmosphere at 300-700℃. x Irregular TiO2 nanoparticles are generated on the surface of the material. On the one hand, nano-TiO2 acts as a wide bandgap semiconductor in Ti3C2T x An insulating barrier is constructed on the surface of the sheet to increase the volume resistivity of the composite material. On the other hand, nano-TiO2 has certain thermal conductivity, which helps the continuity of the thermal network, so that the composite material can still maintain good thermal conductivity and insulation at a low thermal conductive filler content.

[0060] In some specific embodiments, the usage ratio of hydrochloric acid solution, deionized water, sodium fluoride, and Ti3AlC2 powder in the above-mentioned heat-treated Mxene preparation process is 20-30 mL: 20-30 mL: 2 g: 1.5-2 g, and the mass fraction of the hydrochloric acid solution is 36-38%.

[0061] In some specific embodiments, the antioxidant is at least one of 1010, 1076, 168, 626, 300 and DSTDP.

[0062] In some specific embodiments, the lubricant is at least one of calcium stearate, zinc stearate, paraffin wax and polyethylene wax.

[0063] In some specific embodiments, the halogen-free flame-retardant thermally conductive polyolefin material is made by the following steps:

[0064] The raw materials are weighed according to a weight ratio and placed in a mixer for uniform mixing. The raw materials are then transferred to a twin-screw extruder for extrusion and granulation to obtain a halogen-free flame-retardant thermally conductive polyolefin material.

[0065] In some specific embodiments, the mixer speed is 500-1500 rpm, and the mixing time is 15-60 min.

[0066] In some embodiments, the extrusion temperature is 160-190°C.

[0067] In some specific embodiments, the central conductor is a twisted wire core.

[0068] In some specific embodiments, the material of the center conductor is one of a bare copper conductor, a tinned copper conductor, and a nickel-plated copper conductor.

[0069] In some specific embodiments, the braided shielding layer is braided from tinned copper wires, and the braiding density is 90-95%.

[0070] In some specific embodiments, the aluminum foil shielding layer is a polyimide aluminum-plastic composite tape with a thickness of 0.03 mm.

[0071] The technical solution of the present application is illustrated below through specific examples and comparative examples. In the examples and comparative examples, the ethylene-vinyl acetate copolymer is Formosa Plastics 7470M, and the high-density polyethylene is Shanghai Yihe Trading 5110.

[0072] Preparation Example 1

[0073] A heat-treated MXene, the preparation method is as follows:

[0074] 20 mL of hydrochloric acid solution (36 wt%) and 20 mL of deionized water were mixed, and 2 g of sodium fluoride was added. The mixture was stirred at 60 ° C until the sodium fluoride was completely dissolved. Then 1.5 g of Ti3AlC2 powder was added. After ultrasonication for 30 min, the mixture was kept warm and magnetically stirred for 48 h. The mixture was centrifuged, and the precipitate was washed with deionized water and vacuum dried to obtain Ti3C2T x Materials: Ti3C2T x The material was transferred to a muffle furnace and heat treated at 300°C for 4 h in an air atmosphere to obtain heat-treated Mxene.

[0075] Preparation Example 2

[0076] A heat-treated MXene, the preparation method is as follows:

[0077] 25 mL of hydrochloric acid solution (37 wt%) and 30 mL of deionized water were mixed, and 2 g of sodium fluoride was added. The mixture was stirred at 60 ° C until the sodium fluoride was completely dissolved. Then 1.8 g of Ti3AlC2 powder was added. After ultrasonication for 30 min, the mixture was kept warm and magnetically stirred for 48 h. The mixture was centrifuged, and the precipitate was washed with deionized water and vacuum dried to obtain Ti3C2T x Materials: Ti3C2T x The material was transferred to a muffle furnace and heat treated at 500°C for 3 h in an air atmosphere to obtain heat-treated Mxene.

[0078] Preparation Example 3

[0079] A heat-treated MXene, the preparation method is as follows:

[0080] 30 mL of hydrochloric acid solution (38 wt%) and 30 mL of deionized water were mixed and then 2 g of sodium fluoride was added. The mixture was stirred at 60 ° C until the sodium fluoride was completely dissolved. Then 2 g of Ti3AlC2 powder was added. After ultrasonication for 30 min, the mixture was kept warm and magnetically stirred for 48 h. The mixture was centrifuged, and the precipitate was washed with deionized water and vacuum dried to obtain Ti3C2T x Materials: Ti3C2T x The material was transferred to a muffle furnace and heat treated at 700°C for 4 h in an air atmosphere to obtain heat-treated Mxene.

[0081] Preparation Example 4

[0082] A heat-treated Mxene, compared with Preparation Example 1, the only difference is that the heat treatment temperature in Preparation Example 1 is adjusted from "300° C." to "500° C.".

[0083] Preparation Example 5

[0084] A heat-treated Mxene, compared with Preparation Example 1, the only difference is that the heat treatment temperature in Preparation Example 1 is adjusted from "300° C." to "700° C.".

[0085] Example 1

[0086] A new energy vehicle cable, which includes a central conductor, an insulation layer, a braided shielding layer, an aluminum foil shielding layer and an outer sheath layer from the inside to the outside.

[0087] The insulating layer and the outer sheath layer are each independently extruded from a halogen-free flame-retardant thermally conductive polyolefin material, wherein the halogen-free flame-retardant thermally conductive polyolefin material comprises the following raw materials in parts by weight:

[0088] 80 parts of high-density polyethylene, 30 parts of ethylene-vinyl acetate copolymer, 5 parts of heat-treated Mxene of Preparation Example 1, 10 parts of diethyl aluminum hypophosphite, 0.2 parts of 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane, 0.7 parts of phosphatidylserine, 0.1 parts of antioxidant 1010, and 1 part of calcium stearate.

[0089] The halogen-free flame-retardant thermally conductive polyolefin material is prepared by the following steps:

[0090] The raw materials were weighed according to the weight ratio and placed in a mixer, mixed at a speed of 500 rpm for 60 minutes, and then transferred to a twin-screw extruder for extrusion and granulation. The temperature of the twin-screw extruder was 160°C in zone 1, 170°C in zone 2, 180°C in zone 3, 190°C in zone 4, 180°C in zone 5, 170°C in zone 6, and 160°C in zone 7 to obtain a halogen-free flame retardant thermal conductive polyolefin material.

[0091] The central conductor is a stranded wire core, which is formed by twisting 500 bare copper conductors with an outer diameter of 0.16 mm.

[0092] The braided shielding layer is braided from tinned copper wires with a diameter of 0.1 mm, and the braiding density is 95%.

[0093] The aluminum foil shielding layer is a polyimide aluminum-plastic composite tape with a thickness of 0.03 mm.

[0094] The preparation method of the above-mentioned new energy vehicle cable comprises the following steps:

[0095] S1. Extrusion-type die is used to extrude an insulating layer made of halogen-free flame-retardant thermally conductive polyolefin material onto the outside of the central conductor to obtain an insulated core wire;

[0096] S2. Cover the insulated core wire with a tinned copper wire braided mesh, then wrap it with a polyimide aluminum-plastic composite tape, with the aluminum surface adhered to the outer periphery of the braided shielding layer, and the aluminum foil overlap rate is 25%. Finally, an extrusion die is used to extrude and cover the sheath layer made of halogen-free flame-retardant thermal conductive polyolefin material to obtain a new energy vehicle cable.

[0097] Using a twisted wire core as the central conductor helps to enhance the flexibility and bending fatigue resistance of the cable, and adapt to complex installation environments; using halogen-free flame-retardant thermally conductive polyolefin material to prepare the insulation layer and outer sheath layer, while ensuring the insulation performance, significantly improving the heat dissipation effect, which helps to extend the service life of the cable. It is also environmentally friendly and flame-retardant, and can reduce toxic gas emissions in the event of a fire; the double-layer shielding structure and optimized braiding density improve the cable's ability to resist electromagnetic interference and ensure stable signal transmission; the multi-layer insulation design improves the ability to withstand high voltage and prevent corona discharge and partial discharge.

[0098] Example 2

[0099] A new energy vehicle cable, which includes a central conductor, an insulation layer, a braided shielding layer, an aluminum foil shielding layer and an outer sheath layer from the inside to the outside.

[0100] The insulating layer and the outer sheath layer are each independently extruded from a halogen-free flame-retardant thermally conductive polyolefin material, wherein the halogen-free flame-retardant thermally conductive polyolefin material comprises the following raw materials in parts by weight:

[0101] 75 parts of high-density polyethylene, 25 parts of ethylene-vinyl acetate copolymer, 8 parts of heat-treated Mxene of Preparation Example 4, 10 parts of diethyl aluminum hypophosphite, 0.5 parts of γ-aminopropyltriethoxysilane, 2 parts of L-phosphatidylethanolamine, 0.5 parts of antioxidant 10760.5 parts, and 2 parts of zinc stearate.

[0102] The halogen-free flame-retardant thermally conductive polyolefin material is prepared by the following steps:

[0103] The raw materials were weighed according to the weight ratio and placed in a mixer, mixed at a speed of 1000 rpm for 30 minutes, and then transferred to a twin-screw extruder for extrusion and granulation. The temperature of the twin-screw extruder was 160°C in zone 1, 170°C in zone 2, 180°C in zone 3, 190°C in zone 4, 180°C in zone 5, 170°C in zone 6, and 160°C in zone 7 to obtain a halogen-free flame retardant thermal conductive polyolefin material.

[0104] The central conductor is a stranded wire core, which is formed by twisting 500 bare copper conductors with an outer diameter of 0.16 mm.

[0105] The braided shielding layer is braided from tinned copper wires with a diameter of 0.1 mm, and the braiding density is 90%.

[0106] The aluminum foil shielding layer is a polyimide aluminum-plastic composite tape with a thickness of 0.03 mm.

[0107] The preparation method of the new energy vehicle cable is the same as that in Example 1.

[0108] Example 3

[0109] A new energy vehicle cable, which includes a central conductor, an insulation layer, a braided shielding layer, an aluminum foil shielding layer and an outer sheath layer from the inside to the outside.

[0110] The insulating layer and the outer sheath layer are each independently extruded from a halogen-free flame-retardant thermally conductive polyolefin material, wherein the halogen-free flame-retardant thermally conductive polyolefin material comprises the following raw materials in parts by weight:

[0111] 80 parts of high-density polyethylene, 20 parts of ethylene-vinyl acetate copolymer, 10 parts of heat-treated Mxene of Preparation Example 5, 10 parts of diethyl aluminum hypophosphite, 1 part of 3-(triethoxysilyl)propyl succinic anhydride, 4 parts of phospholipid compound, 1681 parts of antioxidant, and 3 parts of polyethylene wax.

[0112] The phospholipid compound consists of phosphatidylserine and L-phosphatidylethanolamine in a mass ratio of 1:1.

[0113] The halogen-free flame-retardant thermally conductive polyolefin material is prepared by the following steps:

[0114] The raw materials were weighed according to the weight ratio and placed in a mixer, mixed at a speed of 1500 rpm for 15 minutes, and then transferred to a twin-screw extruder for extrusion and granulation. The temperature of the twin-screw extruder was 160°C in zone 1, 170°C in zone 2, 180°C in zone 3, 190°C in zone 4, 180°C in zone 5, 170°C in zone 6, and 160°C in zone 7 to obtain a halogen-free flame retardant thermal conductive polyolefin material.

[0115] The central conductor is a stranded wire core, which is formed by twisting 500 bare copper conductors with an outer diameter of 0.16 mm.

[0116] The braided shielding layer is braided from tinned copper wires with a diameter of 0.1 mm, and the braiding density is 90%.

[0117] The aluminum foil shielding layer is a polyimide aluminum-plastic composite tape with a thickness of 0.03 mm.

[0118] The preparation method of the new energy vehicle cable is the same as that in Example 1.

[0119] Example 4

[0120] The new energy vehicle cable is different from Example 1 only in that the "heat-treated Mxene" in the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 1 is replaced by the product obtained in Preparation Example 2.

[0121] Example 5

[0122] The new energy vehicle cable is different from Example 1 only in that the "heat-treated Mxene" in the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 1 is replaced by the product obtained in Preparation Example 3.

[0123] Example 6

[0124] The new energy vehicle cable is different from Example 1 only in that the amount of phosphatidylserine used in the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 1 is adjusted from "0.7 parts by weight" to "2 parts by weight".

[0125] Example 7

[0126] The new energy vehicle cable is different from Example 3 only in that the amount of phosphatidylserine used in the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 3 is adjusted from "4 parts by weight" to "0.7 parts by weight".

[0127] Example 8

[0128] The new energy vehicle cable is different from Example 1 only in that "3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane" in the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 1 is replaced by "γ-aminopropylmethyldiethoxysilane".

[0129] Comparative Example 1

[0130] The new energy vehicle cable is different from Example 1 only in that the amount of heat-treated Mxene used in the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 1 is adjusted from "5 parts by weight" to "2.5 parts by weight".

[0131] Comparative Example 2

[0132] The new energy vehicle cable is different from Example 3 only in that the amount of heat-treated Mxene used in the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 3 is adjusted from "10 parts by weight" to "12.5 parts by weight".

[0133] Comparative Example 3

[0134] The new energy vehicle cable is different from Example 1 in that the "heat-treated Mxene" in the preparation process of the halogen-free flame-retardant thermal conductive polyolefin material in Example 1 is replaced by "Ti3C2T x Materials", Ti3C2T x The material preparation process is the same as that in Preparation Example 1.

[0135] Comparative Example 4

[0136] The new energy vehicle cable is different from Example 1 only in that the phosphatidylserine is removed during the preparation of the halogen-free flame-retardant thermally conductive polyolefin material in Example 1.

[0137] Comparative Example 5

[0138] The new energy vehicle cable is different from Example 1 only in that 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane is removed during the preparation process of the halogen-free flame-retardant thermally conductive polyolefin material in Example 1.

[0139] Halogen-free flame-retardant thermally conductive polyolefin materials for new energy vehicle cables prepared in Examples 1 to 8 and Comparative Examples 1 to 5 were hot-pressed into sheets on a flat vulcanizer to prepare test samples, and performance tests were performed. The test items are as follows:

[0140] Tensile properties: Tested in accordance with GB / T 1040-1992 using a universal electronic tensile testing machine. Specimens were placed horizontally at room temperature for 24 hours before tensile testing. The tensile test was conducted at room temperature. The tensile rate was 200 mm / min, and the specimen thickness was 1 mm.

[0141] Thermal Conductivity: The thermal conductivity of samples at room temperature is measured using the transient hot wire method. In this method, a thin metal wire probe, acting as a linear heat source and temperature sensor, is placed between two 2 mm thick, flat test samples.

[0142] Limiting oxygen index: Tested according to GB / T 2406-1993. Sample size: 100mm×6.5mm×3mm.

[0143] Insulation performance test: Use a volume surface resistivity tester to perform volume resistivity test in accordance with GB / T 1408-2006 standard.

[0144] The results are shown in Table 1:

[0145] Table 1

[0146]

[0147] Analysis of the data recorded in Table 1 shows that the halogen-free flame-retardant thermally conductive polyolefin materials prepared in Examples 1-8 have good mechanical properties, insulation thermal conductivity and flame retardancy. As the insulation layer and sheath layer materials of new energy vehicle cables, they can effectively improve the heat dissipation effect and bending resistance of the cables, thereby extending their service life.

[0148] Specifically, it can be seen from the test results of Example 1 and Comparative Example 1 that the amount of heat-treated MXene is too low, making it difficult to form a complete thermal conductive network and to fully exert a reinforcing effect, resulting in reduced mechanical properties, thermal conductivity, and flame retardancy of the composite material.

[0149] Specifically, it can be seen from the test results of Example 3 and Comparative Example 2 that the amount of heat-treated MXene is too high, which leads to a significant decrease in the mechanical properties of the composite material due to poor dispersibility.

[0150] Specifically, it can be seen from the test results of Example 1 and Comparative Example 3 that the Ti3C2T x The thermal conductivity of the composite material increases slightly, but the volume resistivity decreases significantly. Therefore, compared with Ti3C2T x The material is used as a filler. Using heat-treated Mxene as a filler helps to obtain a composite material with high thermal conductivity and insulation properties.

[0151] Specifically, it can be seen from the test results of Example 1 and Comparative Example 4 that the absence of phosphatidylserine leads to a decrease in the mechanical properties, thermal conductivity, and flame retardancy of the composite material.

[0152] Specifically, it can be seen from the test results of Example 1 and Comparative Example 5 that the absence of 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane leads to a decrease in the mechanical properties, thermal conductivity, and flame retardancy of the composite material.

[0153] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0154] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. New energy vehicle cable, which includes a central conductor, an insulation layer, a braided shielding layer, an aluminum foil shielding layer and an outer sheath layer from the inside to the outside, and is characterized in that: The insulating layer and the outer sheath layer are each independently extruded from a halogen-free flame-retardant thermally conductive polyolefin material, wherein the halogen-free flame-retardant thermally conductive polyolefin material comprises the following raw materials in parts by weight: 70-80 parts of high-density polyethylene, 20-30 parts of ethylene-vinyl acetate copolymer, 5-10 parts of heat-treated Mxene, 10 parts of diethyl aluminum hypophosphite, 0.2-1 parts of silane coupling agent, and 0.7-4 parts of phospholipid compound.

2. The new energy vehicle cable according to claim 1, characterized in that: The heat-treated Mxene is TiO2 / Ti3C2T x Composite materials.

3. The new energy vehicle cable according to claim 1, characterized in that: The silane coupling agent is at least one of epoxy silane, carboxyl silane and amino silane.

4. The new energy vehicle cable according to claim 3, characterized in that: The epoxysilane is at least one of 3-glycidoxypropyltrimethoxysilane, 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane and 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane.

5. The new energy vehicle cable according to claim 3, characterized in that: The carboxyl silane is 3-(triethoxysilyl)propyl succinic anhydride and / or 3-[3-carboxyallylamide]propyl triethoxysilane.

6. The new energy vehicle cable according to claim 3, characterized in that: The aminosilane is at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane and γ-aminopropylethoxydimethylsilane.

7. The new energy vehicle cable according to claim 1, characterized in that: The phospholipid compound is phosphatidylserine and / or L-phosphatidylethanolamine.

8. The new energy vehicle cable according to claim 1 or 2, characterized in that: The preparation method of heat-treated Mxene comprises the following steps: Ti3C2T x The material is transferred to a muffle furnace and heat-treated at 300-700° C. for 2-4 h in an air atmosphere to obtain heat-treated Mxene.

9. The new energy vehicle cable according to claim 8, characterized in that: Ti3C2T x The method for preparing the material comprises the following steps: After mixing hydrochloric acid solution and deionized water, sodium fluoride was added and stirred at 60 °C until sodium fluoride was completely dissolved. Then Ti3AlC2 powder was added and ultrasonicated for 30 minutes. The mixture was kept warm and magnetically stirred for 48 hours. The mixture was centrifuged, the precipitate was washed and vacuum dried to obtain Ti3C2T x Material.

10. The new energy vehicle cable according to claim 9, characterized in that: The usage ratio of hydrochloric acid solution, deionized water, sodium fluoride, and Ti3AlC2 powder is 20-30 mL: 20-30 mL: 2 g: 1.5-2 g.

Images