Cable material for energy storage cable and energy storage cable

Abstract

The application provides a cable material for energy storage cable and an energy storage cable, and belongs to the technical field of cable materials. The cable material is a single component, and raw materials include, in weight parts, 40-60 parts of base resin, 80-150 parts of a halogen-free flame-retardant system, 1.1-3.3 parts of a crosslinking aid, and 1.1-4.5 parts of a functional aid. The base resin includes ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer. The halogen-free flame-retardant system includes magnesium hydroxide, aluminum hydroxide, and intumescent flame retardant, which is compounded by ammonium polyphosphate and melamine according to a mass ratio. The crosslinking aid includes vinyl trimethoxysilane and dicumyl peroxide. The functional aid includes antioxidant, lubricating dispersant, and ultraviolet absorber. The obtained cable material has excellent flame retardancy, mechanical properties and electrical properties, can realize high-speed extrusion, and is suitable for the field of energy storage cable.

Description

Technical Field

[0001] This invention relates to the field of cable materials technology, and in particular to a cable material for energy storage cables and an energy storage cable. Background Technology

[0002] With the rapid development of the new energy industry, energy storage cables, as key components in energy storage systems, are facing increasingly stringent performance and safety requirements. As the core material for energy storage cables, the flame retardancy, environmental friendliness, electrical properties, and mechanical properties of the cable material directly affect the safe and reliable operation of the energy storage system.

[0003] Currently, most energy storage cable materials on the market use polyolefins as the base resin, with added flame retardants, crosslinking agents, and various functional additives to meet specific performance requirements. Regarding flame retardant systems, traditional energy storage cable materials mainly rely on a combination of bromine-based flame retardants (such as decabromodiphenyl ethane) and antimony trioxide synergists. While this flame retardant system offers high efficiency, it poses environmental risks. CN108440816A discloses a halogen-free flame-retardant crosslinkable polyolefin cable material. This material uses a combination of inorganic fillers and phosphorus-nitrogen intumescent flame retardants. Chemical crosslinking improves the dispersibility and compatibility of the inorganic fillers in the base material, thereby enhancing flame retardant performance and physical and mechanical properties.

[0004] Regarding the selection of the matrix resin, CN104893088B proposes a UV-crosslinked low-smoke halogen-free flame-retardant cable material. This cable material uses a combination of low-density polyethylene, ethylene-octene copolymer, and ethylene-vinyl acetate copolymer as the matrix resin, and adds maleic anhydride-grafted polyethylene as a compatibilizer to improve the compatibility between the components. This cable material has good heat aging resistance and can be used for a long time at 125℃.

[0005] To improve the flexibility and cold resistance of cable materials, CN110791007A discloses an ultra-soft, cold-resistant, highly flame-retardant thermoplastic low-smoke halogen-free cable material. This cable material uses polyethylene, ethylene propylene diene monomer (EPDM) rubber, and ethylene-octene copolymer as the matrix resin, and adds a mixture of ethylene butyl acrylate (EBA) and ethylene-octene copolymer (POE) as the toughening resin. This formulation design gives the cable material excellent flexibility and low-temperature performance.

[0006] Regarding improving the heat resistance of cable materials, CN106867090B proposes a high-temperature resistant, flexible, thermoplastic, low-smoke, halogen-free, flame-retardant polyolefin cable material. This cable material uses a matrix resin composed of ethylene copolymer, olefin block copolymer, and compatibilizer, and adds inorganic flame retardants and flame retardant synergists. This formulation design enables the cable material to maintain flame retardant properties while possessing good heat resistance, flexibility, and low-temperature performance.

[0007] For high-temperature applications, CN104530545B discloses a 125°C irradiated cross-linked PE cable material for UL high-temperature electronic wires. This cable material uses a matrix resin composed of linear low-density polyethylene and ethylene-octene copolymer, and adds brominated flame retardants and inorganic flame retardants. The irradiated cross-linking technology improves the product's heat resistance and mechanical properties.

[0008] However, existing energy storage cable materials still have the following problems:

[0009] 1. Environmental limitations: Most high-performance cable materials still rely on bromine-based flame retardants such as decabromodiphenyl ethane. These flame retardants easily release halogenated acid gases and toxic substances such as dioxins when burning, which does not meet the requirements of environmental regulations such as EU RoHS and REACH.

[0010] 2. High specific gravity: The high filler content of traditional brominated flame retardants and antimony trioxide results in a cable material specific gravity typically ≥1.4 g / cm³. 3 This increases the weight of the cable, which is not conducive to the lightweight installation and long-distance laying of energy storage cables;

[0011] 3. Complexity of process: Most existing cable materials adopt a two-component design, which requires the separate preparation of two components and strict control of the specific gravity difference between the two. The production process is complicated and increases the cost of industrial production.

[0012] 4. Insufficient weather resistance: Brominated flame retardants have limited compatibility with the resin matrix and are prone to precipitation with long-term use, which leads to a decrease in the cable's resistance to damp heat and ultraviolet radiation, affecting the long-term reliability of the energy storage system.

[0013] Therefore, there is an urgent need to develop a low-density, halogen-free, flame-retardant, environmentally friendly, single-component design and balanced overall performance cable material for energy storage cables to meet the increasingly higher requirements of modern energy storage systems for cable materials. Summary of the Invention

[0014] In order to address the shortcomings of existing energy storage cable materials in terms of environmental protection, specific gravity, process complexity, and weather resistance, and to achieve the technical effects of low specific gravity, halogen-free flame retardancy, excellent environmental protection, single-component design, and balanced comprehensive performance, this invention provides an energy storage cable material and an energy storage cable using the material.

[0015] To achieve the above objectives, the present invention provides the following solution:

[0016] A cable material for energy storage cables, wherein the cable material is a single component, and by weight, the raw materials include:

[0017] The matrix resin consists of 40-60 parts, the halogen-free flame retardant system consists of 80-150 parts, the crosslinking agent consists of 1.1-3.3 parts, and the functional additive consists of 1.1-4.5 parts.

[0018] The matrix resin includes ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer;

[0019] The halogen-free flame retardant system includes magnesium hydroxide, aluminum hydroxide, and an intumescent flame retardant, wherein the intumescent flame retardant is a mixture of ammonium polyphosphate and melamine in a specific mass ratio.

[0020] The crosslinking aids include vinyltrimethoxysilane and dicumyl peroxide;

[0021] The functional additives include antioxidants, lubricating dispersants, and ultraviolet absorbers.

[0022] Preferably, in the matrix resin, the mass ratio of ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer is 1:0.3-0.5:0.1-0.3.

[0023] Preferably, the ethylene-octene copolymer has a melt index of 8-15 g / 10 min; the metallocene linear low-density polyethylene has a melt index of 20-30 g / 10 min; and the ethylene-methyl acrylate copolymer has a methyl acrylate content of 15-20% and a melt index of 5-10 g / 10 min.

[0024] Preferably, in the halogen-free flame retardant system, the mass ratio of magnesium hydroxide, aluminum hydroxide, and intumescent flame retardant is 1:0.4-0.6:0.2-0.4.

[0025] Preferably, the magnesium hydroxide has an average D50 particle size of 1.5–2.5 μm and a specific surface area of ​​20–30 m². 2 / g; the average D50 particle size of the aluminum hydroxide is 2.0-3.0 μm, and the specific surface area is 15-25 m² / g. 2 / g.

[0026] Preferably, in the intumescent flame retardant, the mass ratio of ammonium polyphosphate to melamine is 3:1.

[0027] Preferably, the crosslinking aid contains 1-3 parts vinyltrimethoxysilane and 0.1-0.3 parts dicumyl peroxide; the functional aid contains 0.5-2 parts antioxidant, 0.5-2 parts lubricating dispersant, and 0.1-0.5 parts ultraviolet absorber.

[0028] Preferably, the specific gravity of the cable material is 1.25–1.35 g / cm³. 3Oxygen index ≥32%, tensile strength ≥10MPa, elongation at break ≥350%, elongation under load ≤80% and permanent deformation ≤10% after cooling in a 200℃×0.2MPa heat extension test, and volume resistivity ≥1×10 at 20℃. 12 Ω·m, at an extrusion speed ≥200m / min in a single screw extruder.

[0029] The present invention also provides a method for preparing the above-mentioned cable material for energy storage cables, comprising the following steps:

[0030] S1. Add the matrix resin, halogen-free flame retardant system, and functional additives to a high-speed mixer according to the specified ratio, and mix at 80-100℃ for 5-10 minutes.

[0031] S2. Add the crosslinking aid to the high-speed mixer after mixing, and continue mixing for 2-3 minutes to obtain the mixture;

[0032] S3. The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 130-170°C and a screw speed of 300-500 r / min to obtain the cable material.

[0033] The present invention also provides an energy storage cable with a cross-sectional area of ​​10-50 mm². 2 The raw materials for this energy storage cable include the aforementioned cable material for energy storage cables.

[0034] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0035] (1) This invention uses a halogen-free flame retardant system (i.e., magnesium hydroxide, aluminum hydroxide, and intumescent flame retardant) to replace traditional bromine-based flame retardants such as decabromodiphenyl ethane and antimony trioxide. No toxic gases are released during combustion, which meets EU environmental standards and satisfies high-end environmental requirements.

[0036] (2) The specific gravity of the cable material of this invention is 1.25-1.35 g / cm³. 3 Compared to the existing technology of ≥1.4g / cm 3 It reduces cable weight by approximately 5-10%, effectively reducing installation difficulty and energy consumption, making it particularly suitable for long-distance laying applications;

[0037] (3) The present invention adopts a single-component design, eliminating the need to prepare two components separately and control the specific gravity difference, which significantly shortens the production process, reduces industrialization costs, and improves production efficiency.

[0038] (4) While ensuring high flame retardancy (oxygen index ≥32%, passing UL94V-0 flame retardancy test), excellent mechanical properties (tensile strength ≥10MPa, elongation at break ≥350%) and processability (high-speed extrusion speed can reach 200m / min or more), this invention improves the weather resistance and long-term reliability of the cable by adding ultraviolet absorbers and optimizing the antioxidant system, making it more suitable for outdoor or complex environment applications of energy storage systems. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0040] Figure 1 A comparison chart of specific gravity and oxygen index of different cable materials provided for this invention;

[0041] Figure 2 A comparison chart of the mechanical properties of different cable materials provided for this invention;

[0042] Figure 3 A comparison chart of the thermal elongation properties and extrusion speeds of different cable materials provided by this invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] like Figure 1 As shown, the present invention provides a cable material for energy storage cables. The cable material is a single component, and by weight, the raw materials include:

[0046] The matrix resin consists of 40-60 parts, the halogen-free flame retardant system consists of 80-150 parts, the crosslinking agent consists of 1.1-3.3 parts, and the functional additive consists of 1.1-4.5 parts.

[0047] The matrix resin includes ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer;

[0048] The halogen-free flame retardant system includes magnesium hydroxide, aluminum hydroxide, and an intumescent flame retardant, wherein the intumescent flame retardant is a mixture of ammonium polyphosphate and melamine in a specific mass ratio.

[0049] The crosslinking aids include vinyltrimethoxysilane and dicumyl peroxide;

[0050] The functional additives include antioxidants, lubricating dispersants, and ultraviolet absorbers.

[0051] Specifically, in the matrix resin, the mass ratio of ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer is 1:0.3-0.5:0.1-0.3.

[0052] Furthermore, the melt index of the ethylene-octene copolymer is 8-15 g / 10 min; the melt index of the metallocene linear low-density polyethylene is 20-30 g / 10 min; and the methyl acrylate content in the ethylene-methyl acrylate copolymer is 15-20%, with a melt index of 5-10 g / 10 min.

[0053] Specifically, in the halogen-free flame retardant system, the mass ratio of magnesium hydroxide, aluminum hydroxide, and intumescent flame retardant is 1:0.4-0.6:0.2-0.4.

[0054] Furthermore, the magnesium hydroxide has an average D50 particle size of 1.5–2.5 μm and a specific surface area of ​​20–30 m². 2 / g; the average D50 particle size of the aluminum hydroxide is 2.0-3.0 μm, and the specific surface area is 15-25 m² / g. 2 / g.

[0055] Furthermore, in the intumescent flame retardant, the mass ratio of ammonium polyphosphate to melamine is 3:1.

[0056] Specifically, the crosslinking aid contains 1 to 3 parts vinyltrimethoxysilane and 0.1 to 0.3 parts dicumyl peroxide; the functional aid contains 0.5 to 2 parts antioxidant, 0.5 to 2 parts lubricating dispersant, and 0.1 to 0.5 parts ultraviolet absorber.

[0057] Furthermore, the specific gravity of the cable material is 1.25–1.35 g / cm³. 3 Oxygen index ≥32%, tensile strength ≥10MPa, elongation at break ≥350%, elongation under load ≤80% and permanent deformation ≤10% after cooling in a 200℃×0.2MPa heat extension test, and volume resistivity ≥1×10 at 20℃. 12 Ω·m, at an extrusion speed ≥200m / min in a single screw extruder.

[0058] In addition, the present invention also provides a method for preparing the above-mentioned cable material for energy storage cables, comprising the following steps:

[0059] S1. Add the matrix resin, halogen-free flame retardant system, and functional additives to a high-speed mixer according to the specified ratio, and mix at 80-100℃ for 5-10 minutes.

[0060] S2. Add the crosslinking aid to the high-speed mixer after mixing, and continue mixing for 2-3 minutes to obtain the mixture;

[0061] S3. The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 130-170°C and a screw speed of 300-500 r / min to obtain the cable material.

[0062] The energy storage cable is manufactured using the aforementioned cable material, and its cross-sectional area is 10–50 mm². 2 .

[0063] The present invention will be further described below through specific embodiments. The described embodiments are only some embodiments of the present invention, and not all embodiments.

[0064] Example 1

[0065] This embodiment provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 50 parts of matrix resin, 120 parts of halogen-free flame retardant system, 2.2 parts of crosslinking agent, and 3.0 parts of functional agent.

[0066] The base resins include ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer, with a mass ratio of 1:0.4:0.2. Specifically, the melt index (190℃, 2.16kg, GB / T3682.1) of the ethylene-octene copolymer is 12 g / 10 min; the melt index (190℃, 2.16kg, GB / T3682.1) of the metallocene linear low-density polyethylene is 25 g / 10 min; and the methyl acrylate content in the ethylene-methyl acrylate copolymer is 18%, with a melt index (190℃, 2.16kg, GB / T3682.1) of 8 g / 10 min.

[0067] The halogen-free flame retardant system comprises magnesium hydroxide, aluminum hydroxide, and an intumescent flame retardant in a mass ratio of 1:0.5:0.3. The magnesium hydroxide has an average D50 particle size of 2.0 μm and a specific surface area of ​​25 m². 2 / g; the average D50 particle size of aluminum hydroxide is 2.5μm, and the specific surface area is 20m². 2 / g. The intumescent flame retardant is a compound of ammonium polyphosphate and melamine in a mass ratio of 3:1.

[0068] The crosslinking aids include 2.0 parts of vinyltrimethoxysilane and 0.2 parts of dicumyl peroxide. The functional aids include 1.5 parts of antioxidant, 1.2 parts of lubricating dispersant, and 0.3 parts of ultraviolet absorber.

[0069] The preparation method of the cable material for this energy storage cable includes the following steps:

[0070] 50 parts of the base resin (including 31.25 parts of ethylene-octene copolymer, 12.5 parts of metallocene linear low-density polyethylene, and 6.25 parts of ethylene-methyl acrylate copolymer), 120 parts of the halogen-free flame retardant system (including 66.67 parts of magnesium hydroxide, 33.33 parts of aluminum hydroxide, and 20 parts of intumescent flame retardant, wherein the intumescent flame retardant is composed of 15 parts of ammonium polyphosphate and 5 parts of melamine), and 3.0 parts of functional additives (including 1.5 parts of antioxidant, 1.2 parts of lubricating dispersant, and 0.3 parts of UV absorber) were added to a high-speed mixer according to the specified ratio and mixed at 90°C for 8 minutes.

[0071] Add 2.2 parts of crosslinking aid (including 2.0 parts of vinyltrimethoxysilane and 0.2 parts of dicumyl peroxide), and continue mixing for 2.5 min;

[0072] The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 150°C and a screw speed of 400 r / min to obtain the cable material.

[0073] The specific gravity of the obtained cable material is 1.30 g / cm³. 3 The oxygen index is 34%, the tensile strength is 12 MPa, the elongation at break is 380%, the elongation under load in the 200℃×0.2 MPa heat extension test is 65%, and the permanent deformation after cooling is 8%. The volume resistivity at 20℃ is 3×10⁻⁶. 12 With a capacity of Ω·m, high-speed extrusion of 250m / min can be achieved.

[0074] This cable material can be used to manufacture cables with a cross-sectional area of ​​25mm². 2 Our energy storage cables possess excellent flame-retardant, mechanical, and electrical properties, meeting the requirements for energy storage cable applications.

[0075] Example 2

[0076] This embodiment provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 40 parts of matrix resin, 80 parts of halogen-free flame retardant system, 1.1 parts of crosslinking agent, and 1.1 parts of functional agent.

[0077] The base resins include ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer, with a mass ratio of 1:0.3:0.1. Specifically, the melt index (190℃, 2.16kg, GB / T3682.1) of the ethylene-octene copolymer is 8 g / 10 min; the melt index (190℃, 2.16kg, GB / T3682.1) of the metallocene linear low-density polyethylene is 20 g / 10 min; and the methyl acrylate content in the ethylene-methyl acrylate copolymer is 15%, with a melt index (190℃, 2.16kg, GB / T3682.1) of 5 g / 10 min.

[0078] The halogen-free flame retardant system comprises magnesium hydroxide, aluminum hydroxide, and an intumescent flame retardant in a mass ratio of 1:0.4:0.2. The magnesium hydroxide has an average D50 particle size of 1.5 μm and a specific surface area of ​​20 m². 2 / g; the average D50 particle size of aluminum hydroxide is 2.0μm, and the specific surface area is 15m². 2 / g. The intumescent flame retardant is a compound of ammonium polyphosphate and melamine in a mass ratio of 3:1.

[0079] The crosslinking aids include 1.0 part vinyltrimethoxysilane and 0.1 part dicumyl peroxide. The functional aids include 0.5 parts antioxidant, 0.5 parts lubricating dispersant, and 0.1 parts ultraviolet absorber.

[0080] The preparation method of the cable material for this energy storage cable includes the following steps:

[0081] Add 40 parts of the base resin (including 28.57 parts of ethylene-octene copolymer, 8.57 parts of metallocene linear low-density polyethylene, and 2.86 parts of ethylene-methyl acrylate copolymer), 80 parts of the halogen-free flame retardant system (including 50 parts of magnesium hydroxide, 20 parts of aluminum hydroxide, and 10 parts of intumescent flame retardant, wherein the intumescent flame retardant is a compound of 7.5 parts of ammonium polyphosphate and 2.5 parts of melamine), and 1.1 parts of functional additives (including 0.5 parts of antioxidant, 0.5 parts of lubricating dispersant, and 0.1 parts of UV absorber) to a high-speed mixer according to the specified ratio, and mix at 80°C for 5 minutes.

[0082] Add 1.1 parts of crosslinking aid (including 1.0 part of vinyltrimethoxysilane and 0.1 part of dicumyl peroxide), and continue mixing for 2 minutes;

[0083] The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 130°C and a screw speed of 300 r / min to obtain the cable material.

[0084] The specific gravity of the obtained cable material is 1.25 g / cm³. 3It has an oxygen index of 32%, a tensile strength of 10 MPa, an elongation at break of 350%, an elongation of 80% under load in a 200℃×0.2 MPa heat extension test with a permanent deformation of 10% after cooling, and a volume resistivity of 1×10 at 20℃. 12 With a capacity of Ω·m, high-speed extrusion of 200m / min can be achieved.

[0085] This cable material can be used to manufacture cables with a cross-sectional area of ​​10mm². 2 The energy storage cable has good flame retardant, mechanical and electrical properties, meeting the requirements for energy storage cable use.

[0086] Example 3

[0087] This embodiment provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 60 parts of matrix resin, 150 parts of halogen-free flame retardant system, 3.3 parts of crosslinking agent, and 4.5 parts of functional agent.

[0088] The base resins include ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer, with a mass ratio of 1:0.5:0.3. Specifically, the melt index (190℃, 2.16kg, GB / T3682.1) of the ethylene-octene copolymer is 15g / 10min; the melt index (190℃, 2.16kg, GB / T3682.1) of the metallocene linear low-density polyethylene is 30g / 10min; and the methyl acrylate content in the ethylene-methyl acrylate copolymer is 20%, with a melt index (190℃, 2.16kg, GB / T3682.1) of 10g / 10min.

[0089] The halogen-free flame retardant system comprises magnesium hydroxide, aluminum hydroxide, and an intumescent flame retardant in a mass ratio of 1:0.6:0.4. The magnesium hydroxide has an average D50 particle size of 2.5 μm and a specific surface area of ​​30 m². 2 / g; the average D50 particle size of aluminum hydroxide is 3.0μm, and the specific surface area is 25m². 2 / g. The intumescent flame retardant is a compound of ammonium polyphosphate and melamine in a mass ratio of 3:1.

[0090] The crosslinking aids include 3.0 parts of vinyltrimethoxysilane and 0.3 parts of dicumyl peroxide. The functional aids include 2.0 parts of antioxidant, 2.0 parts of lubricant and dispersant, and 0.5 parts of ultraviolet absorber.

[0091] The preparation method of the cable material for this energy storage cable includes the following steps:

[0092] 60 parts of the base resin (including 33.33 parts of ethylene-octene copolymer, 16.67 parts of metallocene linear low-density polyethylene, and 10 parts of ethylene-methyl acrylate copolymer), 150 parts of the halogen-free flame retardant system (including 75 parts of magnesium hydroxide, 45 parts of aluminum hydroxide, and 30 parts of intumescent flame retardant, wherein the intumescent flame retardant is a compound of 22.5 parts of ammonium polyphosphate and 7.5 parts of melamine), and 4.5 parts of functional additives (including 2.0 parts of antioxidant, 2.0 parts of lubricating dispersant, and 0.5 parts of UV absorber) were added to a high-speed mixer according to the specified ratio and mixed at 100°C for 10 min.

[0093] Add 3.3 parts of crosslinking aid (including 3.0 parts of vinyltrimethoxysilane and 0.3 parts of dicumyl peroxide), and continue mixing for 3 minutes;

[0094] The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 170°C and a screw speed of 500 r / min to obtain the cable material.

[0095] The specific gravity of the obtained cable material is 1.35 g / cm³. 3 The oxygen index is 36%, the tensile strength is 15 MPa, the elongation at break is 400%, the elongation under load in the 200℃×0.2 MPa heat extension test is 50%, and the permanent deformation after cooling is 5%. The volume resistivity at 20℃ is 5×10⁻⁶. 12 With a capacity of Ω·m, high-speed extrusion of 300m / min can be achieved.

[0096] This cable material can be used to manufacture cables with a cross-sectional area of ​​50mm². 2 Our energy storage cables possess excellent flame-retardant, mechanical, and electrical properties, meeting the requirements for energy storage cable applications.

[0097] Example 4

[0098] This embodiment provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 45 parts of matrix resin, 100 parts of halogen-free flame retardant system, 1.8 parts of crosslinking agent, and 2.3 parts of functional agent.

[0099] The base resins include ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer, with a mass ratio of 1:0.35:0.15. Specifically, the melt index (190℃, 2.16kg, GB / T3682.1) of the ethylene-octene copolymer is 10g / 10min; the melt index (190℃, 2.16kg, GB / T3682.1) of the metallocene linear low-density polyethylene is 22g / 10min; and the methyl acrylate content in the ethylene-methyl acrylate copolymer is 16%, with a melt index (190℃, 2.16kg, GB / T3682.1) of 6g / 10min.

[0100] The halogen-free flame retardant system comprises magnesium hydroxide, aluminum hydroxide, and an intumescent flame retardant in a mass ratio of 1:0.45:0.25. The magnesium hydroxide has an average D50 particle size of 1.8 μm and a specific surface area of ​​22 m². 2 / g; the average D50 particle size of aluminum hydroxide is 2.2μm, and the specific surface area is 18m². 2 / g. The intumescent flame retardant is a compound of ammonium polyphosphate and melamine in a mass ratio of 3:1.

[0101] The crosslinking aids include 1.6 parts vinyltrimethoxysilane and 0.2 parts dicumyl peroxide. The functional aids include 1.0 part antioxidant, 1.0 part lubricating dispersant, and 0.3 parts ultraviolet absorber.

[0102] The preparation method of the cable material for this energy storage cable includes the following steps:

[0103] 45 parts of the base resin (including 30 parts of ethylene-octene copolymer, 10.5 parts of metallocene linear low-density polyethylene, and 4.5 parts of ethylene-methyl acrylate copolymer), 100 parts of the halogen-free flame retardant system (including 58.82 parts of magnesium hydroxide, 26.47 parts of aluminum hydroxide, and 14.71 parts of intumescent flame retardant, wherein the intumescent flame retardant is a compound of 11.03 parts of ammonium polyphosphate and 3.68 parts of melamine), and 2.3 parts of functional additives (including 1.0 part of antioxidant, 1.0 part of lubricating dispersant, and 0.3 parts of UV absorber) were added to a high-speed mixer according to the specified ratio and mixed at 85°C for 7 minutes.

[0104] Add 1.8 parts of crosslinking aid (including 1.6 parts of vinyltrimethoxysilane and 0.2 parts of dicumyl peroxide), and continue mixing for 2.5 min;

[0105] The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 140°C and a screw speed of 350 r / min to obtain the cable material.

[0106] The specific gravity of the obtained cable material is 1.28 g / cm³. 3 The oxygen index is 33%, the tensile strength is 11 MPa, the elongation at break is 370%, the elongation under load in the 200℃×0.2 MPa heat extension test is 70%, and the permanent deformation after cooling is 9%. The volume resistivity at 20℃ is 2×10⁻⁶. 12 With a capacity of Ω·m, high-speed extrusion of 220m / min can be achieved.

[0107] This cable material can be used to manufacture cables with a cross-sectional area of ​​20mm². 2 The energy storage cable has good flame retardant, mechanical and electrical properties, meeting the requirements for energy storage cable use.

[0108] Example 5

[0109] This embodiment provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 55 parts of matrix resin, 130 parts of halogen-free flame retardant system, 2.5 parts of crosslinking agent, and 3.8 parts of functional agent.

[0110] The base resins include ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer, with a mass ratio of 1:0.45:0.25. Specifically, the melt index (190℃, 2.16kg, GB / T3682.1) of the ethylene-octene copolymer is 13 g / 10 min; the melt index (190℃, 2.16kg, GB / T3682.1) of the metallocene linear low-density polyethylene is 28 g / 10 min; and the methyl acrylate content in the ethylene-methyl acrylate copolymer is 19%, with a melt index (190℃, 2.16kg, GB / T3682.1) of 9 g / 10 min.

[0111] The halogen-free flame retardant system comprises magnesium hydroxide, aluminum hydroxide, and an intumescent flame retardant in a mass ratio of 1:0.55:0.35. The magnesium hydroxide has an average D50 particle size of 2.2 μm and a specific surface area of ​​28 m². 2 / g; the average D50 particle size of aluminum hydroxide is 2.8μm, and the specific surface area is 22m². 2 / g. The intumescent flame retardant is a compound of ammonium polyphosphate and melamine in a mass ratio of 3:1.

[0112] The crosslinking aids include 2.3 parts vinyltrimethoxysilane and 0.2 parts dicumyl peroxide. The functional aids include 1.8 parts antioxidant, 1.5 parts lubricating dispersant, and 0.5 parts ultraviolet absorber.

[0113] The preparation method of the cable material for this energy storage cable includes the following steps:

[0114] 55 parts of the base resin (including 32.35 parts of ethylene-octene copolymer, 14.56 parts of metallocene linear low-density polyethylene, and 8.09 parts of ethylene-methyl acrylate copolymer), 130 parts of the halogen-free flame retardant system (including 68.42 parts of magnesium hydroxide, 37.63 parts of aluminum hydroxide, and 23.95 parts of intumescent flame retardant, wherein the intumescent flame retardant is a compound of 17.96 parts of ammonium polyphosphate and 5.99 parts of melamine), and 3.8 parts of functional additives (including 1.8 parts of antioxidant, 1.5 parts of lubricating dispersant, and 0.5 parts of UV absorber) were added to a high-speed mixer according to the specified ratio and mixed at 95°C for 9 minutes.

[0115] Add 2.5 parts of crosslinking aid (including 2.3 parts of vinyltrimethoxysilane and 0.2 parts of dicumyl peroxide), and continue mixing for 2.8 min;

[0116] The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 160°C and a screw speed of 450 r / min to obtain the cable material.

[0117] The specific gravity of the obtained cable material is 1.32 g / cm³. 3 The oxygen index is 35%, the tensile strength is 13.5 MPa, the elongation at break is 390%, the elongation under load in the 200℃×0.2 MPa heat extension test is 60%, and the permanent deformation after cooling is 7%. The volume resistivity at 20℃ is 4×10⁻⁶. 12 With a capacity of Ω·m, high-speed extrusion of 280m / min can be achieved.

[0118] This cable material can be used to manufacture cables with a cross-sectional area of ​​35mm². 2 Our energy storage cables possess excellent flame-retardant, mechanical, and electrical properties, meeting the requirements for energy storage cable applications.

[0119] It should be noted that Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, and Embodiment 5 are all types of cable materials for energy storage cables.

[0120] Comparative Example 1

[0121] This comparative example provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 50 parts of matrix resin, 100 parts of brominated flame retardant system, 2.2 parts of crosslinking aid, and 3.0 parts of functional additives. The matrix resin is an ethylene-octene copolymer; the brominated flame retardant system includes 80 parts of decabromodiphenyl ethane and 20 parts of antimony trioxide; the crosslinking aid includes 2.0 parts of vinyltrimethoxysilane and 0.2 parts of dicumyl peroxide; and the functional additives include 1.5 parts of antioxidant, 1.2 parts of lubricating dispersant, and 0.3 parts of ultraviolet absorber.

[0122] In this comparative example, the preparation method of the cable material for the energy storage cable includes the following steps:

[0123] (1) Add the matrix resin, bromine flame retardant system and functional additives to a high-speed mixer according to the ratio, and mix at 90°C for 8 minutes;

[0124] (2) Add crosslinking aid and continue mixing for 2.5 min;

[0125] (3) The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 150°C and a screw speed of 400 r / min to obtain the cable material.

[0126] The specific gravity of the obtained cable material is 1.50 g / cm³. 3The oxygen index is 28%, the tensile strength is 8 MPa, the elongation at break is 280%, the elongation under load in the 200℃×0.2MPa heat extension test is 120%, and the permanent deformation after cooling is 30%. The volume resistivity at 20℃ is 5×10⁻⁶. 10 With Ω·m, an extrusion speed of 150m / min can be achieved.

[0127] Comparative Example 2

[0128] This comparative example provides a cable material for energy storage cables. The cable material is a two-component system, and by weight: Component A includes 60 parts of matrix resin, 2.0 parts of antioxidant, and 2.0 parts of lubricant and dispersant; Component B includes 100 parts of magnesium hydroxide, 50 parts of aluminum hydroxide, 30 parts of intumescent flame retardant, and 3.3 parts of crosslinking aid; the matrix resin is an ethylene-octene copolymer; the intumescent flame retardant is a compound of ammonium polyphosphate and melamine in a mass ratio of 3:1; the crosslinking aid includes 3.0 parts of vinyltrimethoxysilane and 0.3 parts of dicumyl peroxide.

[0129] In this comparative example, the preparation method of the cable material for the energy storage cable includes the following steps:

[0130] (1) Add component A (matrix resin, antioxidant, lubricant and dispersant) to a high-speed mixer, mix at 100°C for 10 min, and then extrude and granulate to obtain component A;

[0131] (2) Add the raw materials of component B (magnesium hydroxide, aluminum hydroxide, intumescent flame retardant, crosslinking aid) to a high-speed mixer, mix at 100°C for 10 min, and extrude and granulate to obtain component B;

[0132] (3) When using, mix components A and B in a ratio of 1:2, put them into a twin-screw extruder, and extrude them at a barrel temperature of 170°C and a screw speed of 500 r / min.

[0133] The specific gravity of the obtained cable material is 1.42 g / cm³. 3 The oxygen index is 30%, the tensile strength is 9 MPa, the elongation at break is 300%, the elongation under load in the 200℃×0.2MPa heat extension test is 95%, and the permanent deformation after cooling is 25%. The volume resistivity at 20℃ is 8×10⁻⁶. 11 With Ω·m, an extrusion speed of 180m / min can be achieved.

[0134] Comparative Example 3

[0135] This comparative example provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 60 parts of matrix resin, 120 parts of a halogen-free flame retardant system, 2.2 parts of crosslinking agent, and 3.0 parts of functional additives. The matrix resin is linear low-density polyethylene. The halogen-free flame retardant system includes 66.67 parts of magnesium hydroxide, 33.33 parts of aluminum hydroxide, and 20 parts of an intumescent flame retardant (ammonium polyphosphate to melamine mass ratio 3:1). The crosslinking agent includes 2.0 parts of vinyltrimethoxysilane and 0.2 parts of dicumyl peroxide. The functional additives include 1.5 parts of antioxidant, 1.2 parts of lubricating dispersant, and 0.3 parts of ultraviolet absorber.

[0136] In this comparative example, the preparation method of the cable material for the energy storage cable is the same as in Example 1, and the specific gravity of the prepared cable material is 1.40 g / cm³. 3 The oxygen index is 29%, the tensile strength is 7 MPa, the elongation at break is 250%, the elongation under load in the 200℃×0.2MPa heat extension test is 110%, and the permanent deformation after cooling is 28%. The volume resistivity at 20℃ is 3×10⁻⁶. 10 With Ω·m, an extrusion speed of 160m / min can be achieved.

[0137] Comparative Example 4

[0138] This comparative example provides a cable material for energy storage cables. The cable material is a single component, and by weight, its raw materials include: 50 parts of matrix resin, 160 parts of halogen-free flame retardant system, 2.2 parts of crosslinking aid, and 3.0 parts of functional aid. The mass ratio of ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer in the matrix resin is 1:0.4:0.2. The halogen-free flame retardant system includes 100 parts of magnesium hydroxide, 50 parts of aluminum hydroxide, and 10 parts of intumescent flame retardant (ammonium polyphosphate to melamine by a mass ratio of 3:1). The crosslinking aid and functional aid are formulated in the same proportions as in Example 1.

[0139] In this comparative example, the preparation method of the cable material for the energy storage cable is the same as in Example 1, and the specific gravity of the prepared cable material is 1.38 g / cm³. 3 The oxygen index is 27%, the tensile strength is 11 MPa, the elongation at break is 320%, the elongation under load in the 200℃×0.2 MPa heat extension test is 90%, and the permanent deformation after cooling is 22%. The volume resistivity at 20℃ is 2×10⁻⁶. 12 With Ω·m, an extrusion speed of 180m / min can be achieved.

[0140] Reference Figure 1 , Figure 2 and Figure 3 The performance data of the embodiments and the comparative examples were compared, and the results are shown in Table 1.

[0141] Table 1 Performance Data Comparison Table

[0142]

[0143] According to the comparison results between the examples and the comparative examples in Table 1, the cable materials of Examples 1 to 4 are superior to those of Comparative Examples 1 to 4 in terms of specific gravity, oxygen index, tensile strength, elongation at break, thermal elongation, volume resistivity and extrusion speed. Specifically, Comparative Example 1 uses a brominated flame retardant, which has a 15%–20% higher specific gravity and a 17%–25% lower oxygen index than the example, and releases toxic gases upon combustion. In contrast, the halogen-free flame retardant system of the example is more environmentally friendly and has a lower specific gravity. The two-component system of Comparative Example 2 requires additional control of the formulation ratio, and the extrusion speed is reduced by 20%–33% compared to the example, demonstrating the advantages of the single-component design of the example in terms of process simplification and production efficiency. Comparative Example 3 uses a single matrix resin, resulting in a 41.7% decrease in tensile strength and a 37.5% decrease in elongation at break, confirming that the multi-component resin compounding in the example can effectively optimize mechanical properties. After reducing the amount of intumescent flame retardant added in Comparative Example 4, the oxygen index decreased by 14.7%–25%, and the thermal elongation performance deteriorated, indicating that the compounding of inorganic flame retardant and intumescent flame retardant in the example has a good flame retardant synergistic effect.

[0144] Therefore, the cable material and energy storage cable obtained by using the above-mentioned energy storage cable material have excellent flame retardancy, mechanical properties and electrical properties, can be extruded at high speed, and are suitable for the field of energy storage cables.

[0145] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0146] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A cable material for energy storage cables, characterized in that, The cable material is a single component, and by weight, the raw materials include: The matrix resin consists of 40-60 parts, the halogen-free flame retardant system consists of 80-150 parts, the crosslinking agent consists of 1.1-3.3 parts, and the functional additive consists of 1.1-4.5 parts. The matrix resin includes ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer; in the matrix resin, the mass ratio of ethylene-octene copolymer, metallocene linear low-density polyethylene, and ethylene-methyl acrylate copolymer is 1:0.3~0.5:0.1~0.

3. The halogen-free flame retardant system includes magnesium hydroxide, aluminum hydroxide, and a flame retardant compounded from ammonium polyphosphate and melamine in a specific mass ratio; in the halogen-free flame retardant system, the mass ratio of magnesium hydroxide, aluminum hydroxide, and the flame retardant compounded from ammonium polyphosphate and melamine in a specific mass ratio is 1:0.4~0.6:0.2~0.4; in the flame retardant compounded from ammonium polyphosphate and melamine in a specific mass ratio, the mass ratio of ammonium polyphosphate to melamine is 3:

1. The crosslinking aids include vinyltrimethoxysilane and dicumyl peroxide; The functional additives include antioxidants, lubricating dispersants, and ultraviolet absorbers; The specific gravity of the cable material is 1.25~1.35 g / cm³. 3 Oxygen index ≥32%, tensile strength ≥10MPa, elongation at break ≥350%, elongation under load ≤80% and permanent deformation ≤10% after cooling in a 200℃×0.2MPa heat extension test, and volume resistivity ≥1×10 at 20℃. 12 Ω·m.

2. The cable material for energy storage cables according to claim 1, characterized in that, The ethylene-octene copolymer has a melt index of 8-15 g / 10 min; the metallocene linear low-density polyethylene has a melt index of 20-30 g / 10 min; the ethylene-methyl acrylate copolymer has a methyl acrylate content of 15-20% and a melt index of 5-10 g / 10 min.

3. The cable material for energy storage cables according to claim 1, characterized in that, The magnesium hydroxide has an average D50 particle size of 1.5~2.5μm and a specific surface area of ​​20-30m². 2 / g; the average D50 particle size of the aluminum hydroxide is 2.0~3.0μm, and the specific surface area is 15-25m². 2 / g.

4. The cable material for energy storage cables according to claim 1, characterized in that, The crosslinking aid contains 1-3 parts vinyltrimethoxysilane and 0.1-0.3 parts dicumyl peroxide; the functional aid contains 0.5-2 parts antioxidant, 0.5-2 parts lubricating dispersant, and 0.1-0.5 parts ultraviolet absorber.

5. A method for preparing cable material for energy storage cables according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Add the base resin, halogen-free flame retardant system, and functional additives to a high-speed mixer according to the specified ratio, and mix at 80~100℃ for 5~10 minutes. S2. Add the crosslinking agent to the high-speed mixer after mixing, and continue mixing for 2-3 minutes to obtain the mixture; S3. The mixture is fed into a twin-screw extruder and extruded and granulated at a barrel temperature of 130~170℃ and a screw speed of 300~500r / min to obtain the cable material.

6. An energy storage cable having a cross-sectional area of ​​10~50 mm² 2 Its characteristics are, The raw materials for the energy storage cable include the cable material for energy storage cables as described in any one of claims 1 to 4.

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