An anti-compression and anti-torsion energy storage cable and its preparation method

Abstract

The present invention discloses a compression-resistant and torsion-resistant energy storage cable and a preparation method thereof, relating to the technical field of energy storage cables. The compression-resistant and torsion-resistant energy storage cable of the present invention sequentially comprises a cable core, an insulating layer, a lubricating shielding layer and a compression-resistant outer sheath from inside to outside. The compression-resistant outer sheath comprises at least the following raw materials in parts by mass: 70-90 parts of high-density polyethylene; 10-20 parts of low-density polyethylene; 20-30 parts of elastic particles; 30-40 parts of ethylene-vinyl acetate copolymer; 30-40 parts of flame retardant; 5-10 parts of maleic anhydride grafted polyterpolymer ethylene-propylene rubber; 0.1-1 part of antioxidant; 1-2 parts of lubricant; 0.1-1 part of crosslinking agent; 0.1-1 part of co-crosslinking agent. The compression-resistant and torsion-resistant energy storage cable prepared in this application has excellent mechanical properties and electrical properties, and improves the compression and torsion resistance of the energy storage cable.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage cables, and particularly relates to a compression-resistant and torsion-resistant energy storage cable and a preparation method thereof. Background Art

[0002] With the continuous development of society and the widespread application of electrification technology, the quality and performance requirements for wires and cables in all walks of life are getting higher and higher. All along, the function of traditional cables is only for power transmission. However, in some special fields, such as power energy storage systems, special energy storage cables are required to form connections between battery modules, between battery clusters, between battery clusters and busbar boxes, or between battery clusters and energy storage inverters on the DC side of the system, so as to realize the storage and utilization of excess energy. The highest voltage level of the energy storage cable is DC 1500V, and the highest continuous operating temperature of the conductor is 125°C. During use, it needs to face harsh conditions such as battery acid and alkali, severe cold, torsion, and bending, and withstand more severe tests. Therefore, for the insulating material used in energy storage cables, not only conventional properties such as safety, environmental protection, halogen-free, low smoke, and good insulation are required, but also higher requirements are put forward for special properties such as high flame retardancy, acid and alkali resistance, low temperature resistance, high temperature aging resistance, long life, and softness.

[0003] At present, the existing energy storage cable sheath materials are mostly polyethylene materials or polyvinyl chloride materials. However, problems such as poor weather resistance and easy cracking and aging gradually exposed by such materials in harsh working conditions such as severe cold or high temperature have restricted their applications. And since wires and cables are usually circular, during use, most wires and cables will encounter the problem of being squeezed. In mild cases, the wires and cables will be deformed, and in severe cases, the internal structure of the wires and cables will be damaged, and even safety accidents will occur. A shielding layer is also provided on the outer side of the cable core of the energy storage cable. The shielding layer can adopt copper tape shielding or copper mesh shielding. The copper mesh used as the shielding layer is a densely woven mesh with staggered weaving, and the copper wires are relatively thin, which are easily broken under the torsional state. And the copper tape will also tighten the cable core when twisted in the winding direction, causing the cable body to be rigid and not easy to bend, and it cannot be suitable for working in a working condition environment that requires bending or torsion.

[0004] Energy storage cables need to cope with many adverse working environments. However, the current existing energy storage cables are not outstanding in terms of compression resistance and torsion resistance. It is difficult to ensure the insulation and normal operation of wires and cables under complex external forces. Even under complex torsional and bending forces, the wires and cables will be damaged and unable to work, resulting in a short service life of the energy storage cable. Therefore, how to meet the compression-resistant and torsion-resistant service performance required by such cables is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a compression-resistant and torsion-resistant energy storage cable and a preparation method thereof, and solve the following technical problems:

[0006] The existing compression and torsion-resistant energy storage cables have problems of poor compression resistance and poor torsion resistance.

[0007] The object of the present invention can be achieved by the following technical solutions:

[0008] A compression and torsion-resistant energy storage cable successively includes a cable core, an insulating layer, a lubricating shielding layer, and a compression-resistant outer sheath from inside to outside. The compression-resistant outer sheath at least includes the following raw materials in parts by mass:

[0009] 70 - 90 parts of high-density polyethylene; 10 - 20 parts of low-density polyethylene; 20 - 30 parts of elastic particles; 30 - 40 parts of ethylene-vinyl acetate copolymer; 30 - 40 parts of flame retardant; 5 - 10 parts of maleic anhydride grafted polypropylene terpolymer rubber; 0.1 - 1 part of antioxidant; 1 - 2 parts of lubricant; 0.1 - 1 part of crosslinking agent; 0.1 - 1 part of co-crosslinking agent;

[0010] Among them, the elastic particles at least include the following raw materials in parts by mass: 100 parts of ethylene propylene diene monomer / nitrile butadiene rubber composite; 5 - 8 parts of zinc oxide; 1 - 2 parts of stearic acid; 40 - 50 parts of carbon black; 1 - 2 parts of accelerator TMTD; 2 - 3 parts of sulfur; 2 - 4 parts of antioxidant.

[0011] As a further scheme of the present invention: The preparation method of the elastic particles includes the following steps:

[0012] Add ethylene propylene diene monomer, nitrile butadiene rubber, and ethylene-vinyl acetate copolymer into a kneader, and mix under the conditions of a temperature of 140 - 150 °C and a rotation speed of 30 - 40 r / min to obtain an ethylene propylene diene monomer / nitrile butadiene rubber composite;

[0013] Add the ethylene propylene diene monomer / nitrile butadiene rubber composite, zinc oxide, stearic acid, carbon black, accelerator TMTD, sulfur, and antioxidant into an open mill, and mix under the conditions of a temperature of 150 - 160 °C and a rotation speed of 40 - 50 r / min, and then vulcanize on a flat vulcanizer for 15 - 20 min under the condition of a pressure of 20 - 25 MPa to obtain elastic particles.

[0014] As a further scheme of the present invention: The mass ratio of the ethylene propylene diene monomer, the nitrile butadiene rubber, and the ethylene-vinyl acetate copolymer in the elastic particles is 50 - 60:45 - 55:1 - 3.

[0015] As a further scheme of the present invention: The preparation method of the material of the compression-resistant outer sheath at least includes the following steps:

[0016] Prepare raw materials according to parts by weight. Put all the raw materials into a high-speed mixer, with a mixing temperature of 80 - 90 °C and a mixing time of 5 - 10 min. Then put the mixed material into an internal mixer for internal mixing, with an internal mixing temperature of 130 - 170 °C and an internal mixing time of 15 - 25 min to obtain a mixed material.

[0017] Add the said mixed material into a twin-screw extruder for extrusion and pelletizing at 100 - 150 °C to obtain the material for preparing the compressive outer sheath.

[0018] As a further scheme of the present invention: The antioxidant is selected from one or more of pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, distearyl thiodipropionate, dilauryl thiodipropionate, 4,4'-bis(α,α-dimethylbenzyl) diphenylamine or 4,4′-thiobis(6-tert-butyl-3-methylphenol); the lubricant is selected from one or more of zinc stearate, calcium stearate, magnesium stearate, polyethylene wax or ethylene bisstearamide; the flame retardant is a composite inorganic flame retardant; the crosslinking agent is selected from one of 2,5-dimethyl-2,5-di-tert-butylperoxyhexane or dicumyl peroxide; the co-crosslinking agent is one or a mixture of triallyl isocyanurate and trimethylolpropane trimethacrylate.

[0019] A preparation method of a compressive and torsion-resistant energy storage cable as described in any one of the above, at least includes the following steps:

[0020] Form an insulating layer on the surface of the cable core, then form a lubricating shielding layer on the insulating layer, and finally form a compressive outer sheath on the lubricating shielding layer.

[0021] As a further scheme of the present invention: The lubricating shielding layer includes a tinned braided shielding net and lubricating oil, and the lubricating oil is coated on the contact surface between the tinned braided shielding net and the insulating layer, and on the contact surface between the tinned braided shielding net and the compressive outer sheath.

[0022] As a further scheme of the present invention: The lubricating oil at least includes a mixture of petroleum jelly and expanded graphite, and the content of expanded graphite in the lubricating oil is 10 - 20 wt%.

[0023] As a further scheme of the present invention: The cable core is a soft structure conductor stranded by tinned copper wires, and the insulating layer is a ceramized silicone rubber insulating layer.

[0024] The beneficial effects of the present invention:

[0025] The wire and cable proposed by the present invention comprises a cable core, an insulating layer, a lubricating shielding layer and a compressive outer sheath from inside to outside. The cable core and the insulating layer perform the basic functions of the wire and cable, i.e., the basic ability to transmit information. The lubricating shielding layer performs an anti-interference function, and the compressive outer sheath performs a function of protecting the internal structure. In the present invention, a matrix resin system is formed by compounding high-density polyethylene, low-density polyethylene, ethylene-vinyl acetate copolymer and elastic particles to form the compressive outer sheath of the energy storage cable, which has excellent mechanical, physical and electrical properties, and better realizes the excellent properties of the outer sheath material of the energy storage material in terms of high temperature resistance, low temperature resistance, wear resistance, etc., and has good mechanical properties such as compressive resistance, bending resistance and torsional resistance. The lubricating shielding layer provided between the compressive outer sheath and the insulating layer of the present invention has good shielding performance and lubricating performance, and while meeting the shielding function, it can also avoid the torsional damage of the shielding net and improve the torsional resistance of the cable. The energy storage cable of the present invention can be applied to a working environment under complex torsional, pressure and bending forces, and can meet the bending performance and torsional performance of the energy storage cable. Using ethylene propylene diene monomer rubber as the main body ensures the softness, high and low temperature resistance, ozone resistance and aging resistance of the cable material.

[0026] The compressive outer sheath prepared by the present invention uses high-density polyethylene as the main resin, which improves the strength of the material. A small amount of low-density polyethylene is added to increase the toughness of the material, and ethylene-vinyl acetate copolymer and elastic particles are also added to increase the compressive performance of the material. Among them, the elastic particles are a composite material of ethylene propylene diene monomer rubber and nitrile rubber, so that the prepared compressive outer sheath has good compressive strength in low-temperature or high-temperature environments. And ethylene-vinyl acetate copolymer is added during the preparation process of the elastic particles to improve the compatibility of the two rubber particles and further improve the mechanical properties of the elastic particles. The present invention combines high-density polyethylene, low-density polyethylene and rubber-based elastic particles, which can endow the matrix with good compressive resistance, softness and weather resistance, but their compatibility and processing performance are poor. The present invention further adds maleic anhydride-grafted ethylene propylene diene monomer rubber to the matrix system, which can improve the compatibility between the components of the substrate and promote the improvement of the toughness and strength of the material.

[0027] The lubricating shielding layer prepared by the present invention coats lubricating oil on the contact surfaces between the tin-plated braided shielding net and the insulating layer, and between the tin-plated braided shielding net and the compressive outer protective layer. The lubricating oil is a mixture of petroleum jelly and expanded graphite. The petroleum jelly is lubricating, which can reduce the friction between the shielding layer and the insulating layer, as well as between the shielding layer and the compressive outer protective layer, improve the anti-torsion performance of the cable, solve the problem that the tin-plated braided shielding net is prone to breakage under cable torsion, ensure that the shielding layer can have a long service life under the working conditions of frequent torsion and stretching, and the expanded graphite in the lubricating oil can further improve the flame retardancy of the prepared energy storage cable. The elastic particles added to the compressive outer protective layer prepared in the present invention also have a certain oil resistance, which can avoid the overflow of lubricating oil to a certain extent and improve the service life of the prepared energy storage cable. Detailed Embodiments

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0029] Embodiment 1 The preparation method of the lubricating oil includes the following steps:

[0030] Mix 10 parts by mass of petroleum jelly and 1.5 parts by mass of expanded graphite to obtain the lubricating oil.

[0031] Embodiment 2 The preparation method of the elastic particles includes the following steps:

[0032] Add 50 parts by mass of ethylene propylene diene monomer (EPDM 4045), 50 parts by mass of nitrile butadiene rubber (NBR 2707) and 1 part by mass of ethylene-vinyl acetate copolymer (EVA 14 / 5) into a kneader, and mix under the conditions of a temperature of 140 °C and a rotation speed of 30 r / min to obtain an ethylene propylene diene monomer / nitrile butadiene rubber composite material;

[0033] Add the above-prepared ethylene propylene diene monomer / nitrile butadiene rubber composite material, 6 parts by mass of zinc oxide, 1 part by mass of stearic acid, 40 parts by mass of carbon black, 1 part by mass of accelerator TMTD, 2 parts by mass of sulfur and 2 parts by mass of antioxidant into an open mill, and mix under the conditions of a temperature of 150 °C and a rotation speed of 40 r / min, and then vulcanize on a flat vulcanizer for 15 min under the condition of a pressure of 25 MPa to obtain the elastic particles.

[0034] Embodiment 3 The preparation method of the elastic particles includes the following steps:

[0035] Add 60 parts by mass of ethylene propylene diene monomer rubber (EPDM 4045), 50 parts by mass of nitrile butadiene rubber (NBR 2707), and 2 parts by mass of ethylene-vinyl acetate copolymer (EVA 14 / 5) into a kneader, and mix under the conditions of a temperature of 140 °C and a rotation speed of 30 r / min to obtain an ethylene propylene diene monomer rubber / nitrile butadiene rubber composite material;

[0036] Add the above-prepared ethylene propylene diene monomer rubber / nitrile butadiene rubber composite material, 6 parts by mass of zinc oxide, 2 parts by mass of stearic acid, 40 parts by mass of carbon black, 1 part by mass of accelerator TMTD, 2 parts by mass of sulfur, and 2 parts by mass of antioxidant into an open mill, and mix under the conditions of a temperature of 150 °C and a rotation speed of 40 r / min. Then, vulcanize for 15 min on a flat vulcanizer under the condition of a pressure of 25 MPa to obtain elastic particles.

[0037] Example 4 The preparation method of the material for the compressive outer sheath comprises the following steps:

[0038] Add 70 parts by mass of high-density polyethylene (HDPE 5000S), 10 parts by mass of low-density polyethylene (HDPE 1F-7B), 10 parts by mass of the elastic particles prepared in Example 2, 30 parts by mass of ethylene-vinyl acetate copolymer (EVA 14 / 5), 30 parts by mass of montmorillonite / aluminum hydroxide composite inorganic flame retardant, 5 parts by mass of maleic anhydride grafted ethylene propylene diene monomer rubber, 0.5 parts by mass of antioxidant dilauryl thiodipropionate, 1 part by mass of lubricant calcium stearate, 0.5 parts by mass of crosslinking agent dicumyl peroxide, and 0.2 parts by mass of co-crosslinking agent triallyl isocyanurate into a high-speed mixer. The mixing temperature is 90 °C and the mixing time is 5 min. Then, put the mixture into a kneader for kneading. The kneading temperature is 150 °C and the kneading time is 15 min to obtain a mixture;

[0039] Add the said mixture into a twin-screw extruder and carry out extrusion granulation at 100 - 150 °C to obtain the material for preparing the compressive outer sheath.

[0040] The preparation method of the compressive and torsion-resistant energy storage cable comprises the following steps:

[0041] Form an insulating layer on the surface of the cable core with a ceramized silicone rubber insulating layer;

[0042] Coat the lubricating oil prepared in Example 1 on both sides of the tin-plated braided shielding net to form a lubricating shielding layer on the surface of the above insulating layer;

[0043] Then, form a compressive outer sheath on the surface of the above lubricating shielding layer with the material for the compressive outer sheath prepared in this example to obtain a compressive and torsion-resistant energy storage cable.

[0044] Example 5 The preparation method of the material for the compressive outer sheath comprises the following steps:

[0045] Put 70 parts by mass of high-density polyethylene (HDPE 5000S), 10 parts by mass of low-density polyethylene (HDPE 1F-7B), 10 parts by mass of the elastic particles prepared in Example 3, 30 parts by mass of ethylene-vinyl acetate copolymer (EVA 14 / 5), 30 parts by mass of montmorillonite / aluminum hydroxide composite inorganic flame retardant, 5 parts by mass of maleic anhydride-grafted polypropylene ethylene rubber, 0.5 part by mass of antioxidant dilauryl thiodipropionate, 1 part by mass of lubricant calcium stearate, 0.5 part by mass of crosslinking agent dicumyl peroxide and 0.2 part by mass of co-crosslinking agent triallyl isocyanurate into a high-speed mixer. The mixing temperature is 90 °C and the mixing time is 5 min. Then put the mixed material into a mixer for mixing. The mixing temperature is 150 °C and the mixing time is 15 min to obtain a mixed material;

[0046] Add the said mixed material into a twin-screw extruder and carry out extrusion granulation at 100 - 150 °C to obtain the material for preparing the compressive outer sheath.

[0047] In the preparation step of the compressive and torsion-resistant energy storage cable, compared with Example 4, in this example, only the compressive outer sheath material prepared in Example 4 added in Example 4 is replaced with the same mass of the compressive outer sheath material prepared in this example, and the other components and preparation methods are exactly the same as those in Example 4.

[0048] Example 6 The preparation method of the material for the compressive outer sheath includes the following steps:

[0049] Put 80 parts by mass of high-density polyethylene (HDPE 5000S), 15 parts by mass of low-density polyethylene (HDPE 1F-7B), 20 parts by mass of the elastic particles prepared in Example 2, 35 parts by mass of ethylene-vinyl acetate copolymer (EVA 14 / 5), 30 parts by mass of montmorillonite / aluminum hydroxide composite inorganic flame retardant, 8 parts by mass of maleic anhydride-grafted polypropylene ethylene rubber, 0.5 part by mass of antioxidant dilauryl thiodipropionate, 1 part by mass of lubricant calcium stearate, 0.5 part by mass of crosslinking agent dicumyl peroxide and 0.2 part by mass of co-crosslinking agent triallyl isocyanurate into a high-speed mixer. The mixing temperature is 90 °C and the mixing time is 5 min. Then put the mixed material into a mixer for mixing. The mixing temperature is 150 °C and the mixing time is 15 min to obtain a mixed material;

[0050] Add the said mixed material into a twin-screw extruder and carry out extrusion granulation at 100 - 150 °C to obtain the material for preparing the compressive outer sheath.

[0051] In the preparation steps of the compression-resistant and torsion-resistant energy storage cable, compared with Example 4, in this example, the compression-resistant outer sheath material prepared in Example 4 added in Example 4 is simply replaced with the same mass of the compression-resistant outer sheath material prepared in this example, and the remaining components and preparation methods are exactly the same as those in Example 4.

[0052] Example 7 The preparation method of the material for the compression-resistant outer sheath includes the following steps:

[0053] Put 80 parts by mass of high-density polyethylene (HDPE 5000S), 15 parts by mass of low-density polyethylene (HDPE 1F-7B), 20 parts by mass of the elastic particles prepared in Example 3, 35 parts by mass of ethylene-vinyl acetate copolymer (EVA 14 / 5), 30 parts by mass of montmorillonite / aluminum hydroxide composite inorganic flame retardant, 8 parts by mass of maleic anhydride grafted polypropylene terpolymer rubber, 0.5 part by mass of antioxidant dilauryl thiodipropionate, 1 part by mass of lubricant calcium stearate, 0.5 part by mass of crosslinking agent dicumyl peroxide and 0.2 part by mass of co-crosslinking agent triallyl isocyanurate into a high-speed mixer, with a mixing temperature of 90 °C and a mixing time of 5 min. Then, put the mixture into a kneader for kneading, with a kneading temperature of 150 °C and a kneading time of 15 min to obtain a mixture;

[0054] Add the mixture into a twin-screw extruder and carry out extrusion granulation at 100-150 °C to obtain the material for preparing the compression-resistant outer sheath.

[0055] In the preparation steps of the compression-resistant and torsion-resistant energy storage cable, compared with Example 4, in this example, the compression-resistant outer sheath material prepared in Example 4 added in Example 4 is simply replaced with the same mass of the compression-resistant outer sheath material prepared in this example, and the remaining components and preparation methods are exactly the same as those in Example 4.

[0056] Comparative Example 1 The preparation method of the compression-resistant and torsion-resistant energy storage cable includes the following steps:

[0057] Form an insulating layer on the surface of the cable core with a ceramized silicone rubber insulating layer;

[0058] Form a shielding layer on the surface of the above insulating layer with an uncoated lubricated tin-plated braided shielding net;

[0059] Then, form a compression-resistant outer sheath on the surface of the above shielding layer with the material of the compression-resistant outer sheath prepared in Example 2 to obtain a compression-resistant and torsion-resistant energy storage cable.

[0060] Comparative Example 2 The preparation method of the compression-resistant and torsion-resistant energy storage cable includes the following steps:

[0061] In the preparation steps of the compression-resistant outer sheath material, compared with Example 4, in this comparative example, elastic particles are simply not added, and the remaining components and preparation methods are exactly the same as those in Example 4.

[0062] In the preparation steps of the compression and torsion resistant energy storage cable, compared with Example 4, in this comparative example, the equal mass of the compression outer sheath material prepared in Example 4 added in Example 4 is simply replaced with the compression outer sheath material prepared in this comparative example, and the remaining components and preparation methods are exactly the same as those in Example 4.

[0063] Comparative Example 3 In the preparation steps of the compression and torsion resistant energy storage cable, compared with Comparative Example 2, the tin-plated braided shielding net formed in this comparative example is not coated with lubricating oil, and the remaining components and preparation methods are exactly the same as those in Comparative Example 2.

[0064] Performance testing

[0065] Torsion resistance performance test: The cable samples of Examples 4 - 7 and Comparative Examples 1 - 3 should be tested at an ambient temperature of 20°C ± 1°C. The cable samples are first twisted clockwise by 1080°, then restored to the natural state, then twisted counterclockwise by 1080°, and then restored to the natural state again. This is taken as one cycle, and a total of 5000 cycles of tests are carried out. The torsion speed is 720° / min - 1080° / min. During this period, a thermal cycle test of 8h of power-on heating and 16h of natural cooling is carried out. During the power-on period, the conductor should be stabilized at the operating temperature of the cable of 90°C. The power-on and cooling processes should run through the entire test process. After completing the tests specified in the above test procedures, the surface of the specimen should be visually inspected for no cracks and distortion phenomena, and no breakdown should occur in the 5min AC withstand voltage test at 3.5U 0 (U 0 represents the rated power frequency voltage between the conductor and the ground or the metal shield for cable design), and the partial discharge should not be greater than 10pA·s at 1.73U 0 voltage. After all the tests are completed, the cable is dissected, and it is determined whether there are cracks in each part of the cable; the test results are shown in Table 1;

[0066] Mechanical strength test. The mechanical strength of the cable samples of Examples 4 - 7 and Comparative Examples 1 - 3 is tested using the cable environmental stress cracking resistance (ESCR) test described in GB / T 2951 - 2008 "General Test Methods for Insulating and Sheathing Materials of Cables and Optical Fibre Cables", and the table is sorted out; the test results are shown in Table 1;

[0067] Compression resistance performance test. The permanent deformation rate and the deformation rate under load of the cable samples obtained in Examples 3 - 6 and Comparative Examples 1 - 3 are tested in accordance with GB / T 2951–2008; the test results are shown in Table 1;

[0068] Table 1: Statistical table of performance test data of specimens of Examples 4 - 7 and Comparative Examples 1 - 3

[0069]

[0070] As can be seen from Table 1, the anti-compression and anti-torsion energy storage cable prepared in this application has good mechanical strength, anti-compression performance and anti-torsion performance. In Comparative Example 1, lubricating oil was not coated on the tinned braided shield, and in the anti-torsion performance test of the obtained energy storage cable, there was a phenomenon of partial rupture inside the cable. In Comparative Example 2, elastic particles were not added to the prepared anti-compression outer sheath, and the permanent deformation rate and the deformation rate under load of the obtained energy storage cable increased, and the anti-compression performance decreased. In Comparative Example 3, neither the shielding layer nor the outer sheath was modified, and the anti-compression performance and anti-torsion performance of the obtained energy storage cable were not improved.

[0071] The above has described in detail an embodiment of the present invention, but the content described is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A compression and torsion resistant energy storage cable, characterized in that: From the inside to the outside, it includes a cable core, an insulating layer, a lubricating shielding layer and a pressure-resistant outer sheath, and the pressure-resistant outer sheath includes at least the following raw materials in parts by weight: 70-90 parts of high-density polyethylene; 10-20 parts of low-density polyethylene; 20-30 parts of elastic particles; 30-40 parts of ethylene-vinyl acetate copolymer; 30-40 parts of flame retardant; 5-10 parts of maleic anhydride grafted polyethylene propylene rubber; 0.1-1 parts of antioxidant; 1-2 parts of lubricant; 0.1-1 parts of crosslinking agent; 0.1-1 parts of auxiliary crosslinking agent; The elastic particles include at least the following raw materials in parts by weight: 100 parts of EPDM rubber / nitrile rubber composite material; 5-8 parts of zinc oxide; 1-2 parts of stearic acid; 40-50 parts of carbon black; 1-2 parts of accelerator TMTD; 2-3 parts of sulfur; and 2-4 parts of antioxidant.

2. The compression-resistant and torsion-resistant energy storage cable according to claim 1 is characterized in that: The method for preparing the elastic particles comprises the following steps: Adding EPDM rubber, nitrile rubber and ethylene-vinyl acetate copolymer into an internal mixer, mixing at a temperature of 140-150° C. and a rotation speed of 30-40 r / min to obtain an EPDM rubber / nitrile rubber composite material; The EPDM rubber / nitrile rubber composite material, zinc oxide, stearic acid, carbon black, accelerator TMTD, sulfur and antioxidant are added to an open mill, mixed at a temperature of 150-160° C. and a rotation speed of 40-50 r / min, and then vulcanized on a flat vulcanizer for 15-20 minutes at a pressure of 20-25 MPa to obtain elastic particles.

3. The compression-resistant and torsion-resistant energy storage cable according to claim 2 is characterized in that: The mass ratio of the EPDM rubber, the nitrile rubber and the ethylene-vinyl acetate copolymer in the elastic particles is 50-60:45-55:1-3.

4. The compression-resistant and torsion-resistant energy storage cable according to claim 1, characterized in that: The method for preparing the material of the compression-resistant outer sheath comprises at least the following steps: Prepare raw materials according to the weight components, put all the raw materials into a high-speed mixer, mix at 80-90°C, mix for 5-10 minutes, then put the mixture into a banbury mixer for kneading at 130-170°C for 15-25 minutes to obtain a mixture; The mixed material is added into a twin-screw extruder and extruded at 100-150° C. to obtain the material for preparing the compression-resistant outer protective layer.

5. The compression-resistant and torsion-resistant energy storage cable according to claim 4 is characterized in that: The antioxidant is selected from one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, tris[2,4-di-tert-butylphenyl]phosphite, distearyl thiodipropionate, dilauryl thiodipropionate, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine or 4,4'-thiobis(6-tert-butyl-3-methylphenol), the lubricant is selected from one or more of zinc stearate, calcium stearate, magnesium stearate, polyethylene wax or ethylene bisstearamide, the flame retardant is a composite inorganic flame retardant, the crosslinking agent is selected from one of 2,5-dimethyl-2,5-di-tert-butyl peroxide or diisopropylbenzene peroxide, and the auxiliary crosslinking agent is one or a mixture of triallyl isocyanurate and trimethylolpropane trimethacrylate.

6. A method for preparing a compression-resistant and torsion-resistant energy storage cable according to any one of claims 1 to 5, characterized in that: At least the following steps are included: An insulating layer is formed on the surface of the cable core, a lubricating shielding layer is then formed on the insulating layer, and finally a pressure-resistant outer sheath is formed on the lubricating shielding layer.

7. The method for preparing the compression-resistant and torsion-resistant energy storage cable according to claim 6, characterized in that: The lubricating shielding layer comprises a tinned braided shielding mesh and lubricating oil, and the lubricating oil is coated on the contact surface between the tinned braided shielding mesh and the insulating layer, and on the contact surface between the tinned braided shielding mesh and the pressure-resistant outer sheath.

8. The method for preparing the compression-resistant and torsion-resistant energy storage cable according to claim 7, characterized in that: The lubricating oil at least comprises a mixture of petroleum jelly and expanded graphite, and the content of the expanded graphite in the lubricating oil is 10-20wt%.

9. The method for preparing a compression-resistant and torsion-resistant energy storage cable according to claim 6, characterized in that: The cable core is a tinned copper wire twisted soft structure conductor, and the insulating layer is a ceramic silicone rubber insulating layer.

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