Halogen-free energy storage cable insulation material and preparation method and application thereof

Abstract

The invention relates to a halogen-free energy storage cable insulation material and a preparation method and application thereof. The halogen-free energy storage cable insulation material comprises the following raw material components in parts by weight: 15-30 parts of an ethylene-vinyl acetate copolymer; 5-10 parts of a polyolefin elastomer; 5 to 10 parts of polyolefin resin; 5-10 parts of ethylene propylene diene monomer; 25 to 35 parts of modified white carbon black; 10 to 20 parts of kaolin; 0.5 to 2 parts of a cross-linking agent; and 4-7 parts of other auxiliary agents. The halogen-free energy storage cable insulation material provided by the invention has good comprehensive properties such as mechanical property, stability, electrical property and aging resistance, and can well meet the standard requirements of cable materials for TUV 2pfg 2693 energy storage systems.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a halogen-free energy storage cable insulation material, a preparation method thereof, and applications thereof. Background Art

[0002] In recent years, with the development of society, the application of wires and cables has become increasingly widespread, and the requirements for their mechanical properties, flame retardancy, electrical properties, and environmental protection have also gradually increased. To improve their flame retardancy, halogen-containing raw materials are often added during the material preparation process in the existing technology, which can easily cause environmental pollution. Polyolefins have excellent dielectric, mechanical, and processing properties and are widely used in various fields of industrial production. However, due to their low melting point, wires and cables made from polyolefins can easily malfunction at higher temperatures and pose safety risks.

[0003] Currently, ethylene propylene rubber (EPR) and cross-linked polyethylene (XLPE) are commonly used as insulation materials for high-voltage cables. However, these two cross-linking materials are mostly chemically cross-linked, resulting in a low degree of cross-linking. Furthermore, byproducts are easily generated during the cross-linking process, causing the accumulation of space charge, leading to partial discharge and breakdown. This in turn reduces the insulation performance of the resulting material, making it difficult to meet the requirements of the TUV2pfg 2693 standard for cable materials for energy storage systems.

[0004] Therefore, designing and providing a halogen-free energy storage cable insulation material that can be used in 125°C irradiation cross-linked halogen-free energy storage cables and has comprehensive properties such as excellent mechanical properties, stability, electrical properties and aging resistance has become an urgent problem to be solved. Summary of the Invention

[0005] To address the above technical issues, the present invention provides a halogen-free energy storage cable insulation material, its preparation method, and its application. The halogen-free energy storage cable insulation material exhibits excellent overall performance, including good mechanical properties, stability, electrical properties, and aging resistance, and can meet the TUV 2PFG 2693 standard for cable materials for energy storage systems.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a halogen-free energy storage cable insulation material, wherein the halogen-free energy storage cable insulation material comprises the following raw material components in parts by weight:

[0008]

[0009] The present invention optimizes the raw material components of the halogen-free energy storage cable insulation material. Through the coordinated effect of the various components, the obtained halogen-free energy storage cable insulation material has excellent mechanical properties, stability, electrical properties and aging resistance, and can thus well meet the TUV 2PFG 2693 standard requirements for cable materials for energy storage systems.

[0010] The weight proportions of ethylene-vinyl acetate copolymer in the halogen-free energy storage cable insulation material of the present invention may be 15 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts or 30 parts; the weight proportions of polyolefin elastomer may be 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts; the weight proportions of polyolefin resin may be 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts; the weight proportions of ethylene propylene diene monomer rubber may be 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts. parts; the weight parts of modified silica can be 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts or 35 parts; the weight parts of kaolin can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 18 parts, 19 parts or 20 parts; the weight parts of the cross-linking agent can be 1.0 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts or 2 parts; the weight parts of other additives can be 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts or 7 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the said range.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution of the present invention, the VA content in the ethylene-vinyl acetate copolymer is 5-30%, for example, it can be 5%, 8%, 10%, 12%, 15%, 18%, 20%, 23%, 25%, 28% or 30%, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the said range.

[0013] Preferably, the melt index of the ethylene-vinyl acetate copolymer at 190°C and 2.16 kg is 2-20 g / 10min, for example, it can be 2 g / 10min, 4 g / 10min, 6 g / 10min, 8 g / 10min, 10 g / 10min, 12 g / 10min, 14 g / 10min, 16 g / 10min, 18 g / 10min or 20 g / 10min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0014] Preferably, the polyolefin elastomer comprises an ethylene-butene copolymer and / or an ethylene-octene copolymer.

[0015] Preferably, the polyolefin elastomer has a melt index of 5-20 g / 10 min at 190 ° C and 2.16 kg, for example, it can be 5 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 14 g / 10 min, 16 g / 10 min, 18 g / 10 min or 20 g / 10 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0016] Preferably, the polyolefin resin is polyethylene resin.

[0017] Preferably, the polyethylene resin includes any one of low-density polyethylene, high-density polyethylene or metallocene polyethylene, or a combination of at least two thereof.

[0018] Preferably, the melt index of the polyolefin resin at 190°C and 2.16 kg is 1-20 g / 20min, for example, it can be 1 g / 10min, 3 g / 10min, 5 g / 10min, 8 g / 10min, 10 g / 10min, 12 g / 10min, 14 g / 10min, 16 g / 10min or 20 g / 10min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0019] Preferably, the EPDM rubber comprises ethylene units, propylene units and non-conjugated diene.

[0020] Preferably, the non-conjugated diene comprises ethylidene norbornene units.

[0021] Preferably, the Mooney viscosity MLI+RM125°C of the EPDM rubber is 15-40, for example, it can be 15, 18, 20, 22, 25, 28, 30, 32, 35, 38 or 40, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0022] As a preferred technical solution of the present invention, the modified silica is prepared by modifying silica with a silane coupling agent.

[0023] Preferably, the silane coupling agent includes any one or a combination of at least two of vinyltrimethoxysilane (YDH-171), γ-aminopropyltriethoxysilane (KH-550), γ-methacryloxypropyltrimethoxysilane (KH-570) or γ-mercaptopropyltrimethoxysilane (KH5-590).

[0024] Preferably, the silica is precipitated silica and / or fumed silica.

[0025] Preferably, based on the mass percentage of white carbon black as 100%, the content of the silane coupling agent is 0.3-3%, for example, it can be 0.3%, 0.5%, 0.8%, 1.0%, 1.5%, 2%, 2.5% or 3%, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range, and further preferably 0.5-1.5%.

[0026] Preferably, the modification is carried out in an organic solvent.

[0027] Preferably, the organic solvent comprises ethanol.

[0028] For example, the modified silica is prepared by the following preparation method, which specifically comprises the following steps:

[0029] 80-100 parts by weight of anhydrous ethanol, 0.05-0.15 parts by weight of a silane coupling agent and 5-15 parts by weight of white carbon black are mixed, ultrasonically dispersed for 20-30 minutes, heated to 50-60° C., stirred for 30-60 minutes, filtered, washed three times with water, and then freeze-dried to obtain coupling agent-modified white carbon black.

[0030] wherein the 80-100 parts by weight may be, for example, 80 parts by weight, 82 parts by weight, 85 parts by weight, 88 parts by weight, 90 parts by weight, 93 parts by weight, 95 parts by weight, 98 parts by weight, or 100 parts by weight; the 0.05-0.15 parts by weight may be, for example, 0.05 parts by weight, 0.06 parts by weight, 0.07 parts by weight, 0.08 parts by weight, 0.09 parts by weight, 0.1 parts by weight, 0.11 parts by weight, 0.12 parts by weight, 0.13 parts by weight, 0.14 parts by weight, or 0.15 parts by weight; and the 20-30 min may be, for example, 20 min, 22 min, 24 min, 26 min, 28 min, 30 min, 32 min, 34 min, 36 min, 38 min, or 40 min. min, 50-60°C can be, for example, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, 30-60 min can be, for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the said range.

[0031] By modifying silica with a silane coupling agent, the present invention significantly improves its compatibility and dispersibility with other raw material components, thereby enhancing the mechanical properties and processability of the resulting halogen-free energy storage cable insulation material. Furthermore, modification with the silane coupling agent effectively reduces silica agglomeration, effectively avoiding the risk of silica agglomeration leading to localized charge accumulation and formation of conductive pathways, which can reduce insulation properties and thus improve insulation stability.

[0032] As a preferred technical solution of the present invention, the cross-linking agent includes triallyl isocyanurate (TAIC) and / or trimethylolpropane triacrylate (TMPTMA).

[0033] As a preferred technical solution of the present invention, the cross-linking agent is a combination of triallyl isocyanurate and trimethylolpropane triacrylate.

[0034] As a preferred technical solution of the present invention, the mass ratio of triallyl isocyanurate and trimethylolpropane triacrylate is (0.8-1.5):1, wherein (0.8-1.5) can be, for example, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0035] The crosslinking agent of the present invention is preferably a combination of TAIC and TMPTMA, which allows for a synergistic effect between the two, thereby enhancing the radiation crosslinking effect and increasing the crosslinking network density. This results in the resulting halogen-free energy storage cable insulation material exhibiting excellent mechanical, stability, and electrical properties even at high temperatures. Furthermore, by optimizing the mass ratio of TAIC to TMPTMA, the resulting halogen-free energy storage cable insulation material can exhibit even better overall mechanical, stability, and electrical properties.

[0036] Preferably, the other additives include antioxidants and / or lubricants.

[0037] Preferably, the weight portion of the antioxidant is 1-2 parts, for example, it can be 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts or 2 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0038] Preferably, the antioxidant includes any one of antioxidant 405, antioxidant 1010, antioxidant 168 or antioxidant 1067, or a combination of at least two of them.

[0039] Preferably, the antioxidant is a combination of antioxidant 405 and antioxidant 1067.

[0040] In the present invention, by further optimizing the antioxidant to be a combination of antioxidant 405 and antioxidant 1067, the two can be better coordinated, thereby making the obtained halogen-free energy storage cable insulation material have excellent aging resistance while also having better heat resistance and stability.

[0041] Preferably, the weight proportion of the lubricant is 3-5 parts, for example, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts or 5 parts, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0042] Preferably, the lubricant includes any one of polyethylene wax, stearate, silicone masterbatch or silicone oil, or a combination of at least two of them.

[0043] In a second aspect, the present invention provides a method for preparing the halogen-free energy storage cable insulation material as described in the first aspect, the preparation method comprising the following steps:

[0044] (1) Melting and granulating the components in the formula to obtain granules;

[0045] (2) extruding the particles of step (1) through an extruder to obtain a wire;

[0046] (3) The wire material described in step (2) is subjected to irradiation cross-linking to obtain the halogen-free energy storage cable insulation material.

[0047] Preferably, the temperature of the banburying and melting in step (1) is 160-175°C, for example, it can be 160°C, 162°C, 164°C, 166°C, 168°C, 170°C, 172°C or 175°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0048] Preferably, the 15-25 min of the banburying and melting in step (1) can be, for example, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min or 25 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0049] Preferably, the internal mixing and melting in step (1) is carried out in an internal mixer.

[0050] Preferably, the granulation method in step (1) comprises extrusion granulation using a single-screw extruder.

[0051] Preferably, the single-screw extruder comprises a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone and a seventh zone connected in sequence, the operating temperature of the first zone is 110-115°C, the operating temperature of the second zone is 115-120°C, the operating temperature of the third zone is 115-120°C, the operating temperature of the fourth zone is 120-125°C, the operating temperature of the fifth zone is 120-125°C, the operating temperature of the sixth zone is 120-130°C, and the operating temperature of the seventh zone is 125-130°C.

[0052] Wherein, the 110-115°C may be, for example, 110°C, 111°C, 112°C, 113°C, 114°C or 115°C, 115-120°C may be, for example, 115°C, 116°C, 117°C, 118°C, 119°C or 120°C, 120-125°C may be, for example, 120°C, 121°C, 122°C, 123°C, 124°C or 125°C, 120-130°C may be, for example, The temperature range of the present invention is 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C. 125-130°C can be, for example, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0053] Preferably, the extruder in step (2) is a wire extruder.

[0054] Preferably, the wire extruder comprises zone I, zone II, zone III and zone IV connected in sequence, the operating temperature of zone I is 150-160°C, the operating temperature of zone II is 165-175°C, the operating temperature of zone III is 165-175°C, and the operating temperature of zone IV is 170-180°C.

[0055] Wherein, the temperature of 150-160°C may be, for example, 150°C, 151°C, 152°C, 153°C, 154°C, 155°C, 156°C, 157°C, 158°C, 159°C or 160°C, the temperature of 165-175°C may be, for example, 165°C, 166°C, 167°C, 168°C, 169°C, 170°C, 171°C, 172°C, 173°C, 174°C or 175°C, and the temperature of 170-180°C may be, for example, 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C or 180°C, as well as specific values ​​between the above-mentioned values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific values ​​included in the range.

[0056] Preferably, the radiation cross-linking method in step (3) comprises using an electron accelerator for radiation cross-linking.

[0057] Preferably, the radiation dose of the radiation cross-linking in step (3) is 5-10 Mrad, for example, it can be 5 Mrad, 6 Mrad, 7 Mrad, 8 Mrad, 9 Mrad or 10 Mrad, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0058] Exemplarily, the method for preparing the halogen-free energy storage cable insulation material specifically includes the following steps:

[0059] (1) adding each component into an internal mixer, performing internal mixing and melting for 15-25 minutes at 160-175° C., and then extruding and granulating through a single-screw extruder to obtain granules; the single-screw extruder comprises a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone and a seventh zone connected in sequence, wherein the working temperature of the first zone is 110-115° C., the working temperature of the second zone is 115-120° C., the working temperature of the third zone is 115-120° C., the working temperature of the fourth zone is 120-125° C., the working temperature of the fifth zone is 120-125° C., the working temperature of the sixth zone is 120-130° C., and the working temperature of the seventh zone is 125-130° C.

[0060] (2) adding the particles described in step (1) into a wire extruder and extruding to obtain a wire; the wire extruder comprises a first zone, a second zone, a third zone and a fourth zone connected in sequence, wherein the operating temperature of the first zone is 150-160° C., the operating temperature of the second zone is 165-175° C., the operating temperature of the third zone is 165-175° C., and the operating temperature of the fourth zone is 170-180° C.

[0061] (3) The wire material of step (2) is cross-linked by irradiation using an electron accelerator, with an irradiation dose of 5-10 Mrad, to obtain the halogen-free energy storage cable insulation material.

[0062] In a third aspect, the present invention provides a use of the halogen-free energy storage cable insulation material as described in the first aspect in a 125° C. irradiation-crosslinked halogen-free energy storage cable.

[0063] The halogen-free energy storage cable insulation material provided by the present invention has good mechanical properties, as well as good durability such as high and low temperature resistance, aging resistance, acid and alkali resistance, and excellent flame retardant properties. It can well meet the TUV 2pfg2693 standard requirements for cable materials for energy storage systems and is therefore suitable for 125°C irradiation cross-linked halogen-free energy storage cables.

[0064] Among them, the halogen-free energy storage cable insulation materials provided by the present invention can well meet the following requirements: tensile strength ≥8MPa, elongation at break ≥125%, deformation rate under load in the thermal extension test ≤100%, permanent elongation after cooling ≤25%, tensile strength retention rate ≥70% and elongation at break retention rate ≥70% in the thermal aging test, shrinkage rate ≤4% in the thermal shrinkage test, tensile strength change rate of -30 to 30% and elongation at break ≥100% in the acid and alkali resistance test, tensile strength change rate and elongation at break change rate of ≤-30% in the compatibility and constant temperature and humidity tests, no cracking in the low-temperature bending test, no conductor leakage after winding and no breakdown in the withstand voltage in the battery acid resistance test, and insulation resistance at 125°C measured resistivity ≥1×10 11 Ω·cm, dielectric strength ≥20 MV / m.

[0065] Compared with the prior art, the present invention has at least the following beneficial effects:

[0066] (1) The present invention optimizes the raw material components of the halogen-free energy storage cable insulation material. Through the coordination of the various components, the obtained halogen-free energy storage cable insulation material has excellent mechanical properties, stability, electrical properties and aging resistance, and can thus well meet the TUV 2pfg 2693 standard requirements for cable materials for energy storage systems.

[0067] (2) The halogen-free energy storage cable insulation material provided by the present invention has a tensile strength of 8.4-9.6 MPa, an elongation at break of 212-247%, good stability (tensile strength change rate is not higher than 24%, elongation at break change rate is not higher than 28%), good aging resistance (tensile strength retention rate is 74-108%, elongation at break retention rate is 72-92%), good battery acid resistance (no conductor leakage after winding, no breakdown under pressure), and an insulation resistance of 1.4×10 11 -4.3×10 11 Ω·cm, dielectric strength 21-26 MV / m. DETAILED DESCRIPTION

[0068] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0069] Unless otherwise specified, the raw materials used in the following examples and comparative examples are commercially available. Some raw material information is as follows:

[0070] Ethylene-vinyl acetate copolymer (EVA resin): Formosa Plastics 7470M, Taiwan Province, China;

[0071] Polyolefin elastomer (POE elastomer): ethylene-octene copolymer, Mitsui DF810;

[0072] Polyolefin resin (PE resin): The mass ratio of high-density polyethylene to linear low-density polyethylene is 1:1; high-density polyethylene was purchased from Dushanzi Petrochemical Company DMDA8920; linear low-density polyethylene was purchased from Sinopec 7042;

[0073] EPDM rubber: Dow Chemical 4725P;

[0074] Silica: Silica SP30S from Shenzhen Jitian Chemical Co., Ltd.

[0075] Lubricant: silicone masterbatch, purchased from Zhejiang Jiahua Co., Ltd. GT500.

[0076] Preparation Example 1

[0077] This preparation example provides a modified silica, which is prepared by the following preparation method, which specifically includes the following steps:

[0078] 90 parts by weight of anhydrous ethanol, 0.1 parts by weight of silane coupling agent KH-570 and 10 parts by weight of white carbon black were mixed, ultrasonically dispersed for 25 minutes, heated to 55°C, stirred for 45 minutes, filtered, washed three times with water, and then freeze-dried to obtain coupling agent-modified white carbon black.

[0079] Preparation Example 2

[0080] This preparation example provides a modified silica, which is prepared by the following preparation method, which specifically includes the following steps:

[0081] 80 parts by weight of anhydrous ethanol, 0.15 parts by weight of silane coupling agent KH-570 and 5 parts by weight of white carbon black were mixed, ultrasonically dispersed for 20 minutes, heated to 50°C, stirred for 60 minutes, filtered, and then washed three times with water. After that, freeze-dried to obtain coupling agent-modified white carbon black.

[0082] Preparation Example 3

[0083] This preparation example provides a modified silica, which is prepared by the following preparation method, which specifically includes the following steps:

[0084] 100 parts by weight of anhydrous ethanol, 0.05 parts by weight of silane coupling agent KH-570 and 15 parts by weight of white carbon black were mixed, ultrasonically dispersed for 30 minutes, heated to 60°C, stirred for 30 minutes, filtered, and then washed three times with water. After that, freeze-dried, coupling agent-modified white carbon black was obtained.

[0085] Example 1

[0086] This embodiment provides a halogen-free energy storage cable insulation material, which includes the following raw material components in parts by weight:

[0087]

[0088] The preparation method of the halogen-free energy storage cable insulation material specifically comprises the following steps:

[0089] (1) Each component is added into an internal mixer, and after internal mixing and melting at 170° C. for 20 min, the components are extruded and granulated through a single-screw extruder to obtain granules; the single-screw extruder comprises a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone and a seventh zone connected in sequence, the working temperature of the first zone is 112° C., the working temperature of the second zone is 118° C., the working temperature of the third zone is 118° C., the working temperature of the fourth zone is 123° C., the working temperature of the fifth zone is 123° C., the working temperature of the sixth zone is 125° C., and the working temperature of the seventh zone is 128° C.

[0090] (2) adding the particles described in step (1) into a wire extruder and extruding the wire; the wire extruder comprises a first zone, a second zone, a third zone and a fourth zone connected in sequence, wherein the operating temperature of the first zone is 155° C., the operating temperature of the second zone is 170° C., the operating temperature of the third zone is 170° C., and the operating temperature of the fourth zone is 175° C.

[0091] (3) The wire material of step (2) is cross-linked by irradiation using an electron accelerator, with an irradiation dose of 8 Mrad, to obtain the halogen-free energy storage cable insulation material.

[0092] Example 2

[0093] This embodiment provides a halogen-free energy storage cable insulation material, which includes the following raw material components in parts by weight:

[0094]

[0095] The preparation method of the halogen-free energy storage cable insulation material specifically comprises the following steps:

[0096] (1) The components are added into an internal mixer, and after internal mixing and melting at 160° C. for 25 min, the components are extruded and granulated through a single-screw extruder to obtain granules; the single-screw extruder comprises a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone and a seventh zone connected in sequence, wherein the working temperature of the first zone is 110° C., the working temperature of the second zone is 115° C., the working temperature of the third zone is 115° C., the working temperature of the fourth zone is 120° C., the working temperature of the fifth zone is 120° C., the working temperature of the sixth zone is 120° C., and the working temperature of the seventh zone is 125° C.

[0097] (2) adding the particles described in step (1) into a wire extruder and extruding them to obtain wire; the wire extruder comprises a first zone, a second zone, a third zone and a fourth zone connected in sequence, wherein the operating temperature of the first zone is 150° C., the operating temperature of the second zone is 165° C., the operating temperature of the third zone is 165° C., and the operating temperature of the fourth zone is 170° C.

[0098] (3) The wire material of step (2) is cross-linked by irradiation using an electron accelerator, with an irradiation dose of 5 Mrad, to obtain the halogen-free energy storage cable insulation material.

[0099] Example 3

[0100] This embodiment provides a halogen-free energy storage cable insulation material, which includes the following raw material components in parts by weight:

[0101]

[0102] The preparation method of the halogen-free energy storage cable insulation material specifically comprises the following steps:

[0103] (1) Each component is added into an internal mixer, and after internal mixing and melting for 15 minutes at 175° C., the components are extruded and granulated through a single-screw extruder to obtain granules; the single-screw extruder comprises a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone and a seventh zone connected in sequence, the working temperature of the first zone is 115° C., the working temperature of the second zone is 120° C., the working temperature of the third zone is 120° C., the working temperature of the fourth zone is 125° C., the working temperature of the fifth zone is 125° C., the working temperature of the sixth zone is 130° C., and the working temperature of the seventh zone is 130° C.

[0104] (2) adding the particles described in step (1) into a wire extruder and extruding the wire; the wire extruder comprises a first zone, a second zone, a third zone and a fourth zone connected in sequence, wherein the operating temperature of the first zone is 160° C., the operating temperature of the second zone is 175° C., the operating temperature of the third zone is 175° C., and the operating temperature of the fourth zone is 180° C.

[0105] (3) The wire material of step (2) is cross-linked by irradiation using an electron accelerator, with an irradiation dose of 10 Mrad, to obtain the halogen-free energy storage cable insulation material.

[0106] Example 4

[0107] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that TAIC is not added, and the reduced weight portion thereof is allocated to TMPTMA. Other raw material components, weight portions, and preparation methods are the same as those in Example 1.

[0108] Example 5

[0109] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that TMPTMA is not added and its reduced weight portion is allocated to TAIC. Other raw material components, weight portions and preparation methods are the same as those in Example 1.

[0110] Example 6

[0111] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that the mass ratio of TAIC and TMPTMA is adjusted from 1.2:1 to 0.5:1, that is, the weight portion of TAIC is 0.5 parts and the weight portion of TMPTMA is 1 part. Other raw material components, weight portions, and preparation methods are the same as those in Example 1.

[0112] Example 7

[0113] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that the mass ratio of TAIC and TMPTMA is adjusted from 1.2:1 to 0.8:1, that is, the weight portion of TAIC is 0.67 parts and the weight portion of TMPTMA is 0.83 parts. Other raw material components, weight portions, and preparation methods are the same as those in Example 1.

[0114] Example 8

[0115] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that the mass ratio of TAIC and TMPTMA is adjusted from 1.2:1 to 1.5:1, that is, the weight portion of TAIC is 0.9 parts and the weight portion of TMPTMA is 0.6 parts. Other raw material components, weight portions, and preparation methods are the same as those in Example 1.

[0116] Example 9

[0117] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that the mass ratio of TAIC and TMPTMA is adjusted from 1.2:1 to 2:1, that is, the weight portion of TAIC is 1 part and the weight portion of TMPTMA is 0.5 part. The other raw material components, weight portions, and preparation method are the same as those in Example 1.

[0118] Example 10

[0119] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that antioxidant 405 is not added, and its reduced weight portion is allocated to antioxidant 1067. Other raw material components, weight portions and preparation methods are the same as those in Example 1.

[0120] Example 11

[0121] This embodiment provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that the antioxidant 1067 is not added, and the reduced weight portion thereof is allocated to the antioxidant 405. The other raw material components, weight portions and preparation method are the same as those in Example 1.

[0122] Comparative Example 1

[0123] This comparative example provides a halogen-free energy storage cable insulation material, which differs from Example 1 only in that the modified silica (Preparation Example 1) is replaced by silica of equal weight parts, and the other raw material components, weight parts and preparation methods are the same as those in Example 1.

[0124] The performance tests of the halogen-free energy storage cable insulation materials obtained in Examples 1-11 and Comparative Example 1 were performed using the following test methods / standards:

[0125] (1) Mechanical properties: Refer to GB / T2951 to test the tensile strength and elongation at break of halogen-free energy storage cable insulation materials.

[0126] (2) Battery acid resistance test: The halogen-free energy storage cable insulation material is heated at 125°C in battery acid (25% sulfuric acid and 75% water, density 1.28 g / cm 3 ) for 240 h, and test whether it has no conductor leakage after winding and can withstand voltage without breakdown.

[0127] (3) Insulation resistance at 125°C: tested using ZC-90F high insulation resistance tester 41229;

[0128] (4) Dielectric strength: Tested according to ASTM D149;

[0129] (5) Air box thermal aging: After heating the halogen-free cable sheath material to 158°C and maintaining it for 168 h, the tensile strength retention rate and the elongation at break retention rate were tested;

[0130] (6) Compatibility test: Test the change rate of tensile strength and elongation at break of halogen-free energy storage cable insulation material after 240 h at 135°C.

[0131] The test results are shown in Table 1 and Table 2.

[0132] Table 1

[0133]

[0134]

[0135] Table 2

[0136]

[0137] The test results show that:

[0138] (1) It can be seen from Examples 1 to 11 that the present invention optimizes the raw material components of the halogen-free energy storage cable insulation material, so that the obtained halogen-free energy storage cable insulation material has excellent mechanical properties (tensile strength of 8.4-9.6 MPa, elongation at break of 212-247%), stability (tensile strength change rate is not higher than 24%, elongation at break change rate is not higher than 28%, and the battery acid resistance test shows no conductor leakage after winding and no breakdown under pressure), and electrical properties (insulation resistance at 125°C is measured to be 1.4×10 11 -4.3×10 11 Ω·cm, dielectric strength 21-26 MV / m) and aging resistance (tensile strength retention rate of 74-108%, elongation at break retention rate of 72-92%), thus being able to well meet the TUV 2pfg 2693 standard requirements for cable materials for energy storage systems.

[0139] (2) By comparing Example 1 with Examples 4 and 5, it can be seen that the present invention can further optimize the type of cross-linking agent to be a combination of TAIC and TMPTMA, so that the two can play a synergistic role, thereby significantly improving the comprehensive performance of the obtained halogen-free energy storage cable insulation material, such as mechanical properties, stability properties and electrical properties. When any one of them is missing, it is impossible to achieve the above-mentioned excellent comprehensive effect.

[0140] (3) By comparing Example 1 with Examples 6-9, it can be seen that the ratio of TAIC to TMPTMA in the cross-linking agent used in Examples 6 and 9 exceeds (0.8-1.5):1, and the tensile strength, 125°C insulation resistance and dielectric strength of the corresponding halogen-free energy storage cable insulation material are reduced, and the change rate of tensile strength and the change rate of elongation at break measured by the compatibility test are increased. This shows that the present invention can further optimize the selection of the component content in the cross-linking agent to enable the obtained halogen-free energy storage cable insulation material to have excellent comprehensive properties such as good mechanical properties, stability and electrical properties.

[0141] (4) By comparing Example 1 with Examples 10 and 11, it can be seen that the present invention can further optimize the type of antioxidant to be a combination of antioxidants 405 and 1067, so that the two can play a synergistic role, thereby better improving the thermal aging performance and stability of the obtained halogen-free energy storage cable insulation material. When any one of them is missing, it is impossible to achieve the above-mentioned excellent comprehensive effect.

[0142] (5) By comparing Example 1 with Comparative Example 1, it can be seen that, compared with conventional silica, the use of the specific modified silica in the present invention can improve the mechanical properties of the obtained halogen-free energy storage cable insulation material, and also significantly improve its stability.

[0143] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A halogen-free energy storage cable insulation material, characterized in that: The halogen-free energy storage cable insulation material comprises the following raw material components in parts by weight:

2. The halogen-free energy storage cable insulation material according to claim 1, characterized in that The VA content in the ethylene-vinyl acetate copolymer is 5-30%; Preferably, the melt index of the ethylene-vinyl acetate copolymer at 190° C. and 2.16 kg is 2-20 g / 10 min.

3. The halogen-free energy storage cable insulation material according to claim 1 or 2, characterized in that: The polyolefin elastomer includes an ethylene-butene copolymer and / or an ethylene-octene copolymer; Preferably, the polyolefin elastomer has a melt index of 5-20 g / 10 min at 190° C. and 2.16 kg.

4. The halogen-free energy storage cable insulation material according to any one of claims 1 to 3, characterized in that The polyolefin resin is a polyethylene resin; Preferably, the polyethylene resin comprises any one of low-density polyethylene, high-density polyethylene or metallocene polyethylene, or a combination of at least two thereof; Preferably, the polyolefin resin has a melt index of 1-20 g / 20 min at 190° C. and 2.16 kg.

5. The halogen-free energy storage cable insulation material according to any one of claims 1 to 4, characterized in that: The EPDM rubber includes ethylene units, propylene units and non-conjugated diene.

6. The halogen-free energy storage cable insulation material according to any one of claims 1 to 5, characterized in that: The modified silica is prepared by modifying silica with a silane coupling agent; Preferably, the silane coupling agent includes any one or a combination of at least two of vinyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane or γ-mercaptopropyltrimethoxysilane; Preferably, the white carbon black is precipitated white carbon black and / or fumed white carbon black; Preferably, based on 100% by mass of white carbon black, the content of the silane coupling agent is 0.3-3%, more preferably 0.5-1.5%.

7. The halogen-free energy storage cable insulation material according to any one of claims 1 to 6, characterized in that: The crosslinking agent includes triallyl isocyanurate and / or trimethylolpropane triacrylate; Preferably, the crosslinking agent is a combination of triallyl isocyanurate and trimethylolpropane triacrylate; Preferably, the mass ratio of triallyl isocyanurate to trimethylolpropane triacrylate is (0.8-1.5):

1.

8. The halogen-free energy storage cable insulation material according to any one of claims 1 to 7, characterized in that: The other additives include antioxidants and / or lubricants; Preferably, the weight portion of the antioxidant is 1-2 parts; Preferably, the antioxidant includes any one of antioxidant 405, antioxidant 1010, antioxidant 168 or antioxidant 1067, or a combination of at least two thereof; Preferably, the weight portion of the lubricant is 3-5 parts; Preferably, the lubricant includes any one of polyethylene wax, stearate, silicone masterbatch or silicone oil, or a combination of at least two of them.

9. A method for preparing a halogen-free energy storage cable insulation material according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: (1) Melting and granulating the components in the formula to obtain granules; (2) extruding the particles of step (1) through an extruder to obtain a wire; (3) irradiating and cross-linking the wire material of step (2) to obtain the halogen-free energy storage cable insulation material; Preferably, the temperature of the banburying and melting in step (1) is 160-175°C; Preferably, the banburying and melting in step (1) is performed for 15-25 minutes; Preferably, the granulation method in step (1) comprises extrusion granulation using a single-screw extruder; Preferably, the single-screw extruder comprises a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone and a seventh zone connected in sequence, wherein the operating temperature of the first zone is 110-115°C, the operating temperature of the second zone is 115-120°C, the operating temperature of the third zone is 115-120°C, the operating temperature of the fourth zone is 120-125°C, the operating temperature of the fifth zone is 120-125°C, the operating temperature of the sixth zone is 120-130°C, and the operating temperature of the seventh zone is 125-130°C; Preferably, the extruder in step (2) is a wire extruder; Preferably, the wire extruder comprises a zone I, a zone II, a zone III and a zone IV connected in sequence, wherein the operating temperature of the zone I is 150-160°C, the operating temperature of the zone II is 165-175°C, the operating temperature of the zone III is 165-175°C, and the operating temperature of the zone IV is 170-180°C; Preferably, the radiation dose of the radiation cross-linking in step (3) is 5-10 Mrad.

10. Use of the halogen-free energy storage cable insulation material according to any one of claims 1 to 8 in a 125°C irradiation-crosslinked halogen-free energy storage cable.

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